Bad header error 400



I have a pdf in an
tag that is in an html page. When I post it to the server in an IE browsers everything is fine; however, when I post in Fire Fox the server return a 400 error. Bad Headers.

Can someone tell me what I am doing wrong..

And also, where do we add the post script for the button object. In the help it shows a script that starts like so: Post("DNS,username stuff); Where do i place this script and which event?

Thanks a lot for any help at all !