Website authentication - passing from internal to external, using .net

[WannaFly]

Not sure how to describe this in the title. We're going to start using a web application that we have user acccounts on another domain for. To access the page, the standard IE username/password box comes up and we have to enter <domain>\<username> with the password.

What i'd like to do is create a ASP.NET webpage that has two boxes, one for username and one for password, that would pass it on to the second website. My reason behind this is that I want to allow the users to only enter their username, and i'll prepend the domain before sending it. I think them having to type the domain every time will be difficult.

I'm pretty sure this isn't possible, but thought i'd ask.

edit: I have no control over the application/web server we're connecting to, but I have my own internal to host the ASP.NET page.

 

[KB]

You would have to configure forms authentication to work across multiple sites:

http://msdn.microsoft.com/en-us/library/eb0zx8fc.aspx

 

[Gunslinger08]

As KB said, use forms auth. You can write a forms auth provider which queries AD for the user's credentials. You'll want to look into the System.DirectoryServices namespace.