How to in PHP? If "THIS" content is submitted, die.

Hey guys,

I'm working on this php mail script. Trying to combat spam.

I know this is simple. But I'm having a tough time. How do I add a statement thats like...

IF { "http://" is submitted in the comments input field } die.
(basically, if anyone tries to submit anything with 'http://' don't process the form.

ELSE { We're cool, do nothing and process the form }

I'd really appreciate it guys. If it gets more complicated I wouldn't have a problem paying someone.

Thanks!

 

<?php

if(strpos($_POST['fieldName'], 'http://') !== false) die();

?>

PHP:

 

thank c4st. Ill give it a shot. I REALLY appreciate it if it works!