ASP.NET Impersonating a Certain User At Run time

[TK]

If you looking for a way to use Forms Authentication with Active Directory,
following web site may be a worth reading as your start point. I'm running
my web application works in Forms Authentication with SQL database now, and
am attempting to switch account database from SQL server to Active
Directory. So I'll try this soon too. :-)

[url]http://msdn.microsoft.com/library/en-us/dnnetsec/html/SecNetHT02.asp?frame=true[/url]

Hope this help,
Good luck.
TK