I’ve noticed recently that a handful of ABS readers have been posting duplicate comments — moreso than one should normally expect. I put myself in their shoes and posted a few test comments myself. It didn’t take long for me to notice that when I refreshed a page that I had just commented on, the prompt would come up asking me if I wanted to resend the data. Naturally, I clicked the first button I could to get rid of that hideous dialog box and, voila, a duplicate post.

Fortunately, we can use the PHP header function to get rid of that nasty form data and prevent duplicate posts.

<?php
//
// [DO SOMETHING WITH FORM DATA]
//
header("location: $_SERVER[PHP_SELF]"); exit();
?>

You can change the location to wherever you want. Effectively, we are using the header function to quietly redirect the user which, in turn, prevents refreshes and back buttons from resending the POST data.