[Header location not working correctly]

Hello,

 

When i want a custom site search i need to process like google "site:600host.net terms" however my php just pulls a blank page when trying to output this i think its to do with :

 

<?php

 

$keywords = $_REQUEST["keywords"];

$keywords2 = "$keywords";

 

 

$lowerCase = strtolower($keywords2);

 

 

header("Location: ".$lowerCase.".html");

?>

 

Thanks any help appreciated!