HTTP 401.3 - Access denied by ACL problem

Hi,

Ive setup a virtual site on IIS 5.1 on win xp. however when i try and view
my site http://localhost/mysite/index.asp i get the following error :

You are not authorized to view this page
You do not have permission to view this directory or page using the
credentials you supplied.

--------------------------------------------------------------------------------

Please try the following:

Click the Refresh button to try again with different credentials.
If you believe you should be able to view this directory or page, please
contact the Web site administrator by using the e-mail address or phone
number listed on the localhost home page.
HTTP 401.3 - Access denied by ACL on resource
Internet Information Services

--------------------------------------------------------------------------------

anyone any ideas how to resolve this ?

thanks

Adam