computer name as user name

[Patricia]

I have Windows XP and FrontPage 2003. When I try to access
the server to publish, I receive the dialogue box for my
user name and password. The user name box is preset with
the computer name and backslash (laptop1\). I cannot
delete the computer name and just use my user name.
However, the server evidently is not recognizing my user
name as laptop1\username.

How can I get the dialogue box to not have the computer
name in the dialogue box?

I do not know if this is a default configuration in XP or
in FrontPage 2003. I also use FrontPage 2002 on Windows
98, but it has never been a problem.

Thanks for any help or direction you can give me.