javascript problem

I am able to run a javascript no problem on one host via iis but
unable on another, both are clustered, the file settings, permissions
and directories are identical. Copied the site over, rebooted server.
The problem is when it reads the javascript it prompts for
authentication, hitting any key will authenticate and display the
script, however, the prompt is unacceptable for users. win2k server
iis 5.0