How to find the login name of a user accessing my website

["Anurag Agarwal" <anurag.agarwal () yahoo com>]

I was wondering if anyone could help me how I can find out the windows login 
of the user, accessing my website. I think i read it somewhere that it gets 
passed as a header information but i am not sure. If anyone of you guys can 
help me with this, i will really appreciate it.

thanks
anurag


-------------------------------------------------------------------------
Sponsored by: Watchfire

AppScan delivers new remediation capabilities, key regulatory compliance 
reporting, and productivity enhancements that dramatically improve, 
automate and streamline users' ability to quickly find, remediate and 
manage web application security vulnerabilities. Change the way you think 
about application security testing - download AppScan today!

https://www.watchfire.com/securearea/appscancamp.aspx?id=701500000008YTE
--------------------------------------------------------------------------