PHP: PHP Proxy

<?php
   if ( !isset($_REQUEST["url"]) ) exit;
 
   $u = $_REQUEST["url"];
   if (substr($u, -0, 7) != "http://") exit;
 
	echo file_get_contents( $u );
 
/*
	function getPage($url, $referer, $timeout, $header=true){
		if(!isset($timeout)) $timeout=30;
		$curl = curl_init();
		if(strstr($referer,"://")){
			curl_setopt ($curl, CURLOPT_REFERER, $referer);
		}
		curl_setopt ($curl, CURLOPT_URL, $url);
		curl_setopt ($curl, CURLOPT_TIMEOUT, $timeout);
		curl_setopt ($curl, CURLOPT_USERAGENT, sprintf("Mozilla/%d.0",rand(4,5)));
		curl_setopt ($curl, CURLOPT_HEADER, (int)$header);
		curl_setopt ($curl, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt ($curl, CURLOPT_SSL_VERIFYPEER, 0);
		$html = curl_exec ($curl);
		curl_close ($curl);
		return $html;
	}
 
	echo getPage( $u, "http://www.websitename.com", "20", false );
*/
?>