DevCurry

Prevent an ASP.NET Application Restart when a Configuration Setting is changed

noreply@blogger.com (Suprotim Agarwal) — Mon, 09 Nov 2009 16:22:00 +0000

A change to configuration settings in your web.config leads to an application restart, affecting the Session and Cache objects. How do you prevent it? The answer is by placing configuration information in an external file. To do so, use the little known attribute called ‘configSource’ as shown below:

<connectionStrings configSource="Myconn.config"/>

In the Myconn.config file, declare the connectionStrings as follows:

<connectionStrings>
<add name="nwstring" connectionString="Data Source=(local);Initial
Catalog=Northwind;Integrated Security=true;"
providerName="System.Data.SqlClient" />
</connectionStrings>

Now you can go ahead and change the connectionString even in a live application without worrying about an application restart!

Make sure you also read about the RestartOnExternalChanges property.

Disabling Debug Mode and Tracing in your ASP.NET applications

noreply@blogger.com (Suprotim Agarwal) — Mon, 09 Nov 2009 00:20:00 +0000

To improve the performance of our ASP.NET application, a recommended practice is to make sure that the application is not deployed with Debug=True attribute.

One of my clients had a production server which hosted multiple websites. Although some of the applications were deployed keeping debug=false, however the rest of the applications had the attribute set to true. They now wanted to control the setting from the machine.config file which would apply to all the applications running on that server.

Here’s a technique that most of the users to not know about. In your machine.config, locate the <system.web> section and add the following entry

That’s it. Now this setting will automatically disable the debug mode and tracing on your applications.

8 Useful FireFox Addons For Web Designers

noreply@blogger.com (Suprotim Agarwal) — Sun, 08 Nov 2009 01:40:00 +0000

Here are some FireFox Add-ons I have found extremely useful while designing web applications. The description of each add-on has been taken from the the official page.

ColorZilla - With ColorZilla you can get a color reading from any point in your browser, quickly adjust this color and paste it into another program. You can Zoom the page you are viewing and measure distances between any two points on the page. The built-in palette browser allows choosing colors from pre-defined color sets and saving the most used colors in custom palettes. DOM spying features allow getting various information about DOM elements quickly and easily. A very useful FireFox extension indeed!

Pencil – A very handy add-on to create diagrams and GUI prototyping

ColorSuckr – Extracts colors from images and builds color schemes

Yet Another Window Resizer - Resize browser window to default screen resolutions

FireShot - A Firefox extension that creates screenshots of web pages (entirely or just visible part). You can also insert text annotations and graphical annotations to the screenshot.

MeasureIt - Draw out a ruler to get the pixel width and height of any elements on a webpage

Web Developer - Adds a menu and a toolbar with various web developer tools

and the last one which is a must have for every web developer/designer

FireBug - Firebug integrates with Firefox to put a wealth of web development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

Using IsDebuggingEnabled in ASP.NET

noreply@blogger.com (Malcolm Sheridan) — Fri, 06 Nov 2009 12:55:00 +0000

A cool feature in the .NET library that I rarely see used is the IsDebuggingEnabled property. This returns a value indicating whether the current HTTP request is in debug mode. I’ve found this useful in the past where I wanted something displayed on the screen to distinguish if the website I’m working on is a debug build or not. To change the compilation of a website, you update the compilation element in the web.config file:

Debugging is off: <compilation debug="false">
Debugging is on: <compilationdebug="true">

The following code demonstrates how to use this property. When page is loaded and debugging is enabled, a JavaScript alert will be displayed:

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head2" runat="server">
<title></title>
<script language="javascript" type="text/javascript"
    src="http://code.jquery.com/jquery-latest.js"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function() {
if ('<%= System.Web.HttpContext.Current.IsDebuggingEnabled %>' == 'True') {
            alert("Debugging enabled!");
        }
});
</script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
       
    </div>
    </form>
</body>
</html>

I find this piece of code very useful if I want to see results that I would not want to be displayed, in a production environment.

Find the Last Day of the Previous Month using C# and VB.NET

noreply@blogger.com (Suprotim Agarwal) — Thu, 05 Nov 2009 12:55:00 +0000

A couple of days ago, I had written a post to Find the First and Last Day of the Current Quarter using C#/VB.NET. A user commented asking how to find the last day of the previous month. Here’s how it can be done:

DateTime dt = DateTime.Now;
DateTime lstDay = new DateTime(dt.Year, dt.Month, 1);
lstDay = lstDay.AddDays(-1);
Console.WriteLine("Month: {0}, LastDate: {1}",lstDay.Month, lstDay.Day);
Console.Read();

VB.NET

Dim dt As DateTime = DateTime.Now
Dim lstDay As New DateTime(dt.Year, dt.Month, 1)
lstDay = lstDay.AddDays(-1)
Console.WriteLine("Month: {0}, LastDate: {1}",lstDay.Month, lstDay.Day)
Console.Read()

Output

The current month is November, so the last day of the previous month (October) is 31.

Check if a Float number falls within a range using Extension Methods

noreply@blogger.com (Suprotim Agarwal) — Wed, 04 Nov 2009 12:55:00 +0000

Extension methods enable you to "add" methods to existing types without creating a new derived type, recompiling, or otherwise modifying the original type. I was having a conversation with a bunch of C# 2.0 developers the other day who were planning to move to C# 3.0 and then 4.0. They had a requirement to check if a number falls within a specific range and wanted to see how this could be done in 3.0. I said use Extension Methods. Here’s some code that checks if a float number falls within a range, using an Extension Method

static class Program
{
    public static void Main(string[] args)
    {
        float number = 23.5f;
        if (number.CheckRange(20.0f, 25.5f))
        {
            Console.WriteLine("In Range");
        }
        else
        {
            Console.WriteLine("Out of Range");
        }
        Console.ReadLine();
    }

    static bool CheckRange(this float num, float min, float max)
    {
        return num > min && num < max;
    }
}

VB.NET

Module Module1
    Public Sub Main(ByVal args() As String)
        Dim number As Single = 23.5F
        If number.CheckRange(20.0F, 25.5F) Then
            Console.WriteLine("In Range")
        Else
            Console.WriteLine("Out of Range")
        End If
        Console.ReadLine()
    End Sub

    <System.Runtime.CompilerServices.Extension()> _
    Private Function CheckRange(ByVal num As Single, _
                                ByVal min As Single, _
                                ByVal max As Single) As Boolean
        Return num > min AndAlso num < max
    End Function
End Module

Add a DotNetKicks button to your Webpage

noreply@blogger.com (Suprotim Agarwal) — Tue, 03 Nov 2009 12:55:00 +0000

DotNetKicks is a popular .NET community based news site. A lot of users use the DotNetKicks social bookmarking button which makes it easier for viewers to submit or ‘kick’ a story. If you have been wondering how to add the DotNetKicks button to every post on your website, here’s the code for it.

<div>
<script type="text/javascript">
document.write('<a href="http://www.dotnetkicks.com/submit?url='+document.location.href+'&title='+document.title+'"> <img src="http://www.dotnetkicks.com/Services/Images/KickItImageGenerator.ashx?url='+document.location.href+'" border="0"></a>');
</script>
</div>

This piece of code determines the URL using ‘document.location.href’ and the Title using ‘document.title’. This information is submitted to the dotnetkicks site when the user click on the link/image. When this code is placed on a page, the output generated is as shown below:

How to access parts of a URL in ASP.NET

noreply@blogger.com (Suprotim Agarwal) — Mon, 02 Nov 2009 12:55:00 +0000

A user asked me the simplest way to dissect a URL and list down the different parts of it in ASP.NET. I advised him to use the URI class. Here’s an example:

Uri someUri = Page.Request.Url;
string urlstr = string.Format(
    "AbsoluteUri: {0}<br/> Scheme: {1}<br/> Host: {2}<br/> Query: {3} ",
    someUri.AbsoluteUri, someUri.Scheme, someUri.Host, someUri.Query);
Response.Write(urlstr);

VB.NET

Dim someUri As Uri = Page.Request.Url
Dim urlstr As String = String.Format( _
     "AbsoluteUri: {0}<br/> Scheme: {1}<br/> Host: {2}<br/> Query: {3} ", _
      someUri.AbsoluteUri, someUri.Scheme, someUri.Host, someUri.Query)
Response.Write(urlstr)

The output is as shown below:

7 Free Tools to Minify your Scripts and CSS

noreply@blogger.com (Suprotim Agarwal) — Sun, 01 Nov 2009 16:50:00 +0000

I have been doing a lot of Client-Side development recently and I have found these 7 tools of great help to improve the performance of the website by ‘shrinking’ the size of JavaScript and CSS files, referenced in the site.

JSMin (JavaScript Minifier) - removes comments and unnecessary whitespace from JavaScript files

JSO (JavaScript Optimizer) - allows you to manage your JavaScript and CSS resources and to reduce the amount of data transfered between the server and the client.

Packer – An online JavaScript Compressor

JSCompress.com – Online tool that uses either JSMin or Packer to compress your files

CSS Compressor – Online tool that compresses your CSS file

DigitalOverload JavaScript Minifier – Online tool that minifies your JavaScript files

and finally the one I use most frequently:

YUI Compressor – A JavaScript minifier designed to be 100% safe and yields a higher compression ratio than most other tools.

Find Out the Image Type without Checking its Extension

noreply@blogger.com (Suprotim Agarwal) — Sat, 31 Oct 2009 13:32:00 +0000

My colleague called up with a query. His application accepted images to be uploaded to a central server. Later the application processed the images and separated them according to the Image Type. They determined the image type by checking the extension of the image uploaded –- a very common practice of detecting the image type.

The issue here was that some images which were actually gif’s were renamed as jpeg’s and then uploaded, which led to faulty image processing. The requirement was to determine the correct image type in the simplest possible way even if the extension was renamed. Here’s what I suggested:

try
{
    Image imgUp = Image.FromFile(Server.MapPath("~/images/abc.jpg"));
    if (imgUp.RawFormat.Equals(ImageFormat.Jpeg))
        Response.Write("JPEG");
    else if (imgUp.RawFormat.Equals(ImageFormat.Gif))
        Response.Write("GIF");
}
catch (Exception ex)
{
}

VB.NET

Try
    Dim imgUp As Image = Image.FromFile(Server.MapPath("~/images/abc.jpg"))
    If imgUp.RawFormat.Equals(ImageFormat.Jpeg) Then
        Response.Write("JPEG")
    ElseIf imgUp.RawFormat.Equals(ImageFormat.Gif) Then
        Response.Write("GIF")
    End If
Catch ex As Exception
End Try

The Image.RawFormat property is extremely useful in this situation to get the file format of the image.

Note: Alternatively you can also use Magic Numbers

How to calculate the CPU Usage Programmatically using C# or VB.NET

noreply@blogger.com (Suprotim Agarwal) — Fri, 30 Oct 2009 11:55:00 +0000

The PerformanceCounter class represents a WindowsNT performance counter component. To read from a performance counter, we first create an instance of the PerformanceCounter class supplying the CategoryName, CounterName, and InstanceName as parameters to the constructor and then call the NextValue() method to take a performance counter reading.

Import the namespaces System.Diagnostics and System.Threading.

static PerformanceCounter cpuUsage;
public static void Main(string[] args)
{
    cpuUsage =
        new PerformanceCounter("Processor", "% Processor Time", "_Total");

    Console.WriteLine(cpuUsage.NextValue() + " %");
    Thread.Sleep(1000);
    Console.WriteLine(cpuUsage.NextValue() + " %");
    Console.Read();
}

VB.NET

Private Shared cpuUsage As PerformanceCounter
Public Shared Sub Main(ByVal args() As String)
    cpuUsage = _
    New PerformanceCounter("Processor", "% Processor Time", "_Total")

    Console.WriteLine(cpuUsage.NextValue() & " %")
    Thread.Sleep(1000)
    Console.WriteLine(cpuUsage.NextValue() & " %")
    Console.Read()
End Sub

Note: Observe that we are calling NextValues() twice and after a delay of 1 second. This is because performance counters need two samples to perform the calculation and the counter value is updated once per second, hence the 1 second delay between the two calls.

The output on running this code is as shown below:

Find Out the Users Connected to a Windows Server using C# or VB.NET

noreply@blogger.com (Suprotim Agarwal) — Thu, 29 Oct 2009 15:20:00 +0000

I was recently asked this question on the forums – How do I find out and list the users connected to a server? I said use Cassia

A standard way of achieving this requirement is to use P/Invoke to access the Windows Terminal Services API. Cassia is a .NET library that acts as a wrapper on the native Windows Terminal Services API.

Cassia has been tested on Windows Server 2008 R2 Beta, Windows Server 2008, Windows Server 2003, Windows XP, and Windows Server 2000. It should work on Windows Vista as well. I haven’t tried it on Windows 7. If any of you does, kindly drop in a comment and let the users know of your experience.

Check out Cassia!

Inject jQuery into a webpage using a FireFox addon - FireQuery

noreply@blogger.com (Malcolm Sheridan) — Wed, 28 Oct 2009 11:55:00 +0000

I found a really cool Firefox addon called FireQuery. This addon enables you to inject jQuery into any web page. This is a nice way to see how any web page behaves with jQuery.

Normally I would write a small article on how to use this technology, but I felt like doing something different so I made a short screencast on FireQuery and how to use it. Hopefully you’ll find it a useful tool as well.

You can watch the screencast here or can see it below:

ASP.NET 4.0 (Beta) Resources

noreply@blogger.com (Suprotim Agarwal) — Wed, 28 Oct 2009 00:08:00 +0000

Here are some useful resources to get started with the latest version of ASP.NET 4.0. Currently ASP.NET 4.0 is in Beta 2

ASP.NET 4.0 and Visual Studio 2010 Beta 2 Released

ASP.NET 4 and Visual Studio 2010 Web Development Beta 2 Overview

ASP.NET 4.0 Training Lessons on Channel 9

Exploring ASP.NET 4.0—Web Forms and Beyond

URL Routing with ASP.NET 4 Web Forms (VS 2010 and .NET 4.0 Series)

Auto-Start ASP.NET Applications (VS 2010 and .NET 4.0 Series)

Channel 9 Video Interviews with the ASP.NET 4 Team

ASP.NET 4 Beta 2 forums

5 jQuery Plugins to Manipulate and add effects to Images

noreply@blogger.com (Suprotim Agarwal) — Mon, 26 Oct 2009 23:47:00 +0000

Here is a list of 5 plugins you can use to manipulate images on client-side. This section has been taken from my eBook 51 Tips, Tricks and Recipes using jQuery and ASP.NET Controls

ImageOverlay - Allows you to display additional information in a translucent pane above an image that gracefully appears when a user hovers over the image

jCrop - jCrop is the quick and easy way to add image cropping functionality to your web application. It combines the ease-of-use of a typical jQuery plugin with a powerful cross-platform DHTML cropping engine that is faithful to familiar desktop graphics applications.

jLoupe - jLoupe adds a "loupe" or "magnifying glass" effect to images. Applying the plugin is as easy as adding the class "jLoupe" to the images you want to enable the effect on.

Magnify - Magnify allows you to easily create a "magnifier" on your images. You just need to create a small and large image which are proportionally sized, configure your markup accordingly and let Magnify do the rest

Reel - Reel is a jQuery plugin which takes an image tag and makes it a live "projection" of pre-built animation frames sequence. Its aim is to provide a 360° view of something or someplace. Like a turntable or a panorama for instance

14 Expression Web 3 Tips and Articles

noreply@blogger.com (Suprotim Agarwal) — Mon, 26 Oct 2009 00:30:00 +0000

If you use Expressions Web 3, check out a link list by Expression Web MVP Minal where she has written some useful Expression Web 3 tips and tricks

14 Microsoft Expression Web 3 Articles and Tips you should read

Here’s an excerpt

Microsoft Expression Web is a ’WYSIWYG’ HTML editor as well as a graphical web design program developed by Microsoft that has today replaced Microsoft FrontPage. Expression Web is a part of the Expression Studio suite. Expression Web provides support for integrating XML, XHTML, XSLT, CSS, ASP.NET and other standard Web technologies into the websites.

I have been using Microsoft Expression Web 2 for quite some time now and I love it! Now with release of Expression Web 3, with features like SuperPreview, Snapshot Panel, new improved toolbars like the Code Toolbar, integration with VSTS, Silverlight support and an enhanced FTP client, you get a better control over your web pages. Believe me, designing has never been so simple and interesting before.

You can also read some additional Tips on Microsoft Expression Web 2 and Tutorials on Microsoft Expression Web 2 written by Minal

Visual Studio 2010 and .NET Framework 4 Beta 2 Released

noreply@blogger.com (Suprotim Agarwal) — Sat, 24 Oct 2009 23:05:00 +0000

Microsoft recently announced (21st October) the immediate availability of Microsoft Visual Studio 2010 Beta 2 and Microsoft .NET Framework 4 Beta 2 to general public

Here are some important links related to the release

Visual Studio 2010 Beta 2 including Express downloads

Channel 9 Video: How to Install the Beta

Visual Studio 2010 and .NET Framework 4 Training Kit - October Preview

Featured Overviews and Walkthroughs

Other important information

Silverlight Toolkit October 2009 Released

noreply@blogger.com (Suprotim Agarwal) — Sat, 24 Oct 2009 00:40:00 +0000

Microsoft has released a new set of Silverlight components and features in the Silverlight Toolkit (October 2009).

A prominent change i found was the support for Visual Studio 2010 and drag & drop support for some key controls.

Here are some important links related to the download:

Silverlight Toolkit October 2009

Silverlight Toolkit October 2009 change list

Online Silverlight 3 Toolkit samples

Windows 7 Launched!

noreply@blogger.com (Suprotim Agarwal) — Thu, 22 Oct 2009 23:09:00 +0000

The much awaited Windows 7 OS was launched today in a keynote by Microsoft’s Chief Executive Steve Ballmer

Here are some useful links:

Read the 32-bit and 64-bit Windows FAQ.

Top 10 reasons to upgrade to Windows 7

Choose the Windows 7 Edition that works best for you.

Daily Offers till October 28th, 2009

Purchase it on Amazon

Microsoft Windows 7 Home Premium Upgrade
Microsoft Windows 7 Professional Upgrade
Microsoft Windows 7 Ultimate Upgrade
Microsoft Windows 7 Home Premium
Microsoft Windows 7 Ultimate
Microsoft Windows 7 Professional

51 Tips, Tricks and Recipes with jQuery and ASP.NET Controls eBook Released!

noreply@blogger.com (Suprotim Agarwal) — Wed, 21 Oct 2009 17:17:00 +0000

I am glad to announce the release of my eBook 51 Tips, Tricks and Recipes with jQuery and ASP.NET Controls. In the first book of its kind on using jQuery with ASP.NET Controls, I show you how to use jQuery to solve some common and not-so-common client-side programming challenges while dealing with ASP.NET Controls.

You can download the Table of Contents and 5 Sample Chapters of the eBook before buying.

You can purchase the eBook over here

Last Chance to Pre-Order my EBook – 51 Recipes with jQuery and ASP.NET Controls

noreply@blogger.com (Suprotim Agarwal) — Tue, 20 Oct 2009 14:16:00 +0000

If you have not yet pre-ordered my EBook - 51 Tips, Tricks and Recipes with jQuery and ASP.NET Controls, then here’s the last chance to pre-order the EBook at a discounted price. This offer will expire in 13 hours from now!

The EBook will be released tomorrow (October 21st, 2009).

You can download the Table of Contents and 5 Sample Chapters of the upcoming EBook before purchasing.

Pre-Order the EBook here

Display Currency Symbols using ISO standards in ASP.NET

noreply@blogger.com (Suprotim Agarwal) — Mon, 19 Oct 2009 11:55:00 +0000

I stumbled across an interesting question about localization/globalization recently. The user wanted to print currency symbols using the ISO standards and wanted to find out if there was an easy way to do so using ASP.NET

Yes, there is! Use the RegionInfo.ISOCurrencySymbol Property. Here’s how

string symbol = RegionInfo.CurrentRegion.ISOCurrencySymbol;

Response.Write(symbol);

VB.NET

Dim symbol As String = RegionInfo.CurrentRegion.ISOCurrencySymbol

Response.Write(symbol)

The output on my system is USD, which is according to the ISO 4217 standards

Microsoft Ajax Library Preview 6 and Ajax Minifier

noreply@blogger.com (Suprotim Agarwal) — Sun, 18 Oct 2009 11:55:00 +0000

Microsoft recently announced a new update to Microsoft Ajax Library (Preview 6) and introduced the Microsoft Ajax Minifier.

What is the Ajax Library Preview 6?

The Ajax Library is a pure JavaScript library that enables you to build highly interactive Ajax applications. You can use the Microsoft Ajax Library in both ASP.NET Web Forms and ASP.NET MVC applications and this library works with most of the modern browsers

What is Ajax Minifier?

In simple words, this tool improves the performance of your websites by reducing the size of your JavaScript files

Here are some important links to help you out with this new update

Microsoft Ajax Library Preview 6 - Download link

Announcing Microsoft Ajax Library (Preview 6) and the Microsoft Ajax Minifier - ScottGu’s blog

Announcing Microsoft Ajax Library Preview 6 - Channel 9

Entirely unobtrusive and imperative templates with Microsoft Ajax Library Preview 6

Let Me Bing That For You – New Service announcement

noreply@blogger.com (Suprotim Agarwal) — Sat, 17 Oct 2009 23:33:00 +0000

Many a times on the forums, I have seen users ask very basic questions that can easily be ‘searched out’. Answerers usually respond to these basic question by guiding the original poster to a search engine and tell them what to search. WAWOT (What a waste of time!)

Here’s how you can now help this OP with some style. Many of you must be familiar with lmgtfy.com or Let me Google that for you

Maarten Balliauw, Juliën Hanssens and Phil Haack got together and created a new website called Let Me Bing That For You

Let Me Bing That For You is a service for our lazy friends who are just too lazy to search out for answers on their own. Here’s how the service works. Assuming the user asked you a query ‘How to lose your Job’. Here’s how you can teach him how to search

- Go to Let Me Bing That For You

- Type in the users query ‘How to lose your Job’ in the search box and click the search button

- The service provides you a link to pass on to that lazy bum

The link guides the user step by step on how to Bing that query. Check the results here :)

http://tinyurl.com/yfd4vbd

Go Search Go!!

Allow Only Alphanumeric Characters in a TextBox using jQuery

noreply@blogger.com (Suprotim Agarwal) — Fri, 16 Oct 2009 13:55:00 +0000

In this short post, I will demonstrate how to allow only alphanumeric characters in a TextBox. This article is a sample chapter from my upcoming EBook called 51 Tips, Tricks and Recipes with jQuery and ASP.NET Controls. The chapter content has been modified a little to publish it as a blog post. Also please note that for demonstration purposes, I have included JavaScript and CSS into the same file. Ideally, these resources should be created in separate folders for maintainability.

Requirement:

Users should be allowed to enter only Alphabets and Numbers in a TextBox. Non-alphanumeric characters should be disallowed. You also want to prevent users from copying and pasting non-alphanumeric characters into the TextBox.

Solution:

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Allow Only Alphanumeric Characters in a TextBox</title>
    <link href="../CSS/Demos.css" rel="stylesheet" type="text/css" />
    <script type='text/javascript'
        src='../Scripts/jquery-1.3.2.min.js'>
    </script>
  
    <script type="text/javascript">
        $(function() {
            $('input.alpha[$id=tb1]').keyup(function() {
                if (this.value.match(/[^a-zA-Z0-9 ]/g)) {
                    this.value = this.value.replace(/[^a-zA-Z0-9 ]/g, '');
                }
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div class="bigDiv">
        <h2>Allow Only Alphanumeric Characters in a TextBox</h2>
        <asp:TextBox ID="tb1" runat="server" class="alpha"
            Text="Try entering Non alphanumeric char"
            ToolTip="Try entering Non alphanumeric char"/>
         <br /><br />
         Tip: Examples of some non-alphanumeric characters <br />
         are ~!@~#$%^&* and so on.
    </div>
    </form>
</body>
</html>

Explanation:

The code shown above matches a regular expression /[^a-zA-Z0-9 ]/g that finds all characters that are not alphabets or numbers. If the user enters a character that is an alphabet or number, the character is replaced with an empty string. Observe the space after ‘9’ to allow whitespaces. Since we are capturing the keyup event, we are also preventing copying and pasting of non-alphanumeric characters. I have observed people using the keypress event to handle this requirement, but remember that in IE, keypress does not behave as expected for non-character keys.

As Yehuda Katz says – “My mantra has always been: keydown/keyup if you want to know the key that was pressed; keypress if you want to know what text was detected”

Note: Javascript can be disabled, so always validate the user input on server side

Tip: If you want to accept only numbers, use /[^0-9 ]/g and for accepting only alphabets, use /[^a-zA-Z ]/g

Browsers Supported:

IE 7, IE 8, Firefox 3, Chrome 2, Safari 4

Useful Links:

http://ejohn.org/blog/keypress-in-safari-31/

http://docs.jquery.com/Events/keyup

LIVE DEMO

There are plenty of such similar tips that I will be covering in my upcoming EBook over here 51 Tips, Tricks and Recipes with jQuery and ASP.NET Controls