how to prevent getting the variables after a browser reload function.

I created a forum with php3. But when the user has posted his article, if he reloads the page, my script re-insert the post into my forum file... I encountered this problem in other forums, moreover I'm not decided to use a database for a single problem like this ... Anyone can help ? --- Being a newbie hurts sometimes ... ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com