how to find UserName of client on server???

thanks for reply ,
But HttpContext.Current.User.Identity.Name or 
HttpContext.Current.Request.ServerVariables["LOGON_USER"] (as per above link) is not working after deploying project on IIS.
It will show the result of server machine only not a client side machine .. plz tell me if u knw how to do this for client side???

Hi Check following links once and i think and these will helps to you.
assuming that you're not using ASP.NET forms authentication mode,
(if you do, you can get username from session)
try using this code:

Dim userName() As String = Split(HttpContext.Current.User.Identity.Name,"\")
userName(0) '// contains Machine name or Domain name
userName(1) '// contains Username


 
http://www.codeproject.com/KB/asp/request_server_variables.aspx
let me know if any issues,
Thanks and Regards,
V.S.R.K.Raju..