Right now when I type in http://portwebsite/home/ my current ASP application is asking for the username and password and checking for the existing user in the database.

I developed a single sign on chek in .Net using Active Directory so when user type in http://portalwebsite/home/ it should check the current windows user authentication which I already developed in .net and then if they are authenticated.....it should directly redirect to the ASP page http://portalwebsite/home/home/ and if not then it should ask for the username and passowrd by my current existing ASP check at http://portalwebsite/home/

Can you please guide me how do i co-relate my both application ?

I appreciate your help.

Well, the problem is that ASP and ASP.NET can't really "talk" to each other very well.

For example, they can *NOT* share session variables, and more than likely you are going to want to use Session variables to keep track of logged-in users.

But there are several ways to get around the problem. Probably the best way is to use a database table that is designed just for holding session information for *both* ASP and ASP.NET. And then you can use Response.Redirect from the ASP.NET signin and include a querystring that in turn holds an encrypted version of the userid or sessionid for the current user. If you use an encryption algorithm and password known only to you--and especially if you include something like the time of day in the encryption--then you should be reliably safe (after all, ASP session ids are just integers that are encrypted and stored in cookies, so you are even safer than that).