stop form submittion when reload button is pressed

[simeonC]

I have a form with many if statements and else statements. It works fine. However when I press the refresh button the form is submitted once again every time i hit the refresh button. how do i stop this from happening

[mac_gyver]

after you have finished processing the form data, redirect to the exact same URL of that page so that the browser won't continue to submit the post data when that URL is requested.

[simeonC]

with the header()

function???