Secure ASP.NET sites from XSS

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetsec/html/THCMCh21.asp

Use the following module:
http://support.microsoft.com/kb/887289

If you think you can just hard code a few chars to prevent it, try
http://www.shocking.com/~rsnake/xss.html