How to handle 404 error in ASP.NET

1. Add following section in web.config
<customErrors mode="On">
<error statusCode="404" redirect="~/error404.aspx" />
</customErrors>

2. Get wrong page from query string
string from = Request.QueryString["aspxerrorpath"];

http://rayaspnet.blogspot.ca/2012/08/handling-exceptions-and-404-errors-in.html

Validators and Javascript in asp.net

ASP.NET Validation in Depth
http://msdn.microsoft.com/en-us/library/aa479045.aspx

How to detect session tiomeout

http://aspalliance.com/520_Detecting_ASPNET_Session_Timeouts.2

How to fix missed Navigate Backward and Forward buttons in Visual Studio

In VS Click Tools,
Import and Export Settings,
select Import Selected environment settings and click Next,
select Yes, save my current settings and click Next,
select General Development Settings, and click Finish.


Or use shortcut: Ctrl+- and Ctrl Shift +-
http://blogs.msdn.com/b/zainnab/archive/2010/03/01/navigate-backward-and-navigate-forward-vstipedit0024.aspx

How to submit once in ASP.NET webform by jquery?

Add two properties into server side button:
UseSubmitBehavior="False"
OnClientClick="$('.Buttons').attr('disabled', 'true');"