problems with Word Attached to web page

I want to post a link to a word document on aweb page. I coipied theword doc
to a folder in my web. Then put a button on a page that links to that word
document.

This works fine, from the page, you click and the word document opens. But
when you hit Back to go back to the original page, you are promtped for a
user and password. If you hit cancel you go back ok.

How do i change it so that the pgm does not ask for a password?