php? contact form?

how do i intergrate a serverside php scripting to make a simple contact
form in lenya?

<?php
	//declare our assets 
	$name = stripcslashes($_POST['name']);
	$emailAddr = stripcslashes($_POST['email']);
	$comment = stripcslashes($_POST['message']);
	$subject = stripcslashes($_POST['subject']);	
	$contactMessage =  
		"Message:
		$comment 

		Name: $name
		E-mail: $emailAddr

		Sending IP:$_SERVER[REMOTE_ADDR]
		Sending Script: $_SERVER[HTTP_HOST]$_SERVER[PHP_SELF]";
		
		//send the email 
		mail('[email protected]', $subject, $contactMessage);
		echo('success'); //return success callback
?>

this is the code im using, but if i try and call it, I get an error.

I simply do not understand why this script which works every other time
ive used it fails on lenya