Use proxy server in PHP

How to use proxy server in PHP.

<?php
// First get the Free proxy list from here
// http://hidemyass.com/proxy-list/search-284460

set_time_limit(0) ;
$t1=time();
$urltopost = "http://amitkgaur.blogspot.com/";

// $urltopost = http://www.xyz.com/t3resultpage.aspx?type=p=test1&q=test2&rid=7851
// $datatopost = array (
//  "firstname" => "Amit",
// "lastname" => "Gaur",
// "blog" => "http://amitkgaur.blogspot.com/",
// );

 $crl = curl_init ($urltopost);
 curl_setopt ($crl, CURLOPT_POST, true);
 curl_setopt($crl, CURLOPT_RETURNTRANSFER, 1);
 curl_setopt($crl, CURLOPT_PROXY, "115.248.234.254:3128");
 curl_setopt($crl, CURLOPT_PROXYPORT, 3128); 
 //curl_setopt ($crl, CURLOPT_POSTFIELDS, $datatopost);
 curl_setopt ($crl, CURLOPT_RETURNTRANSFER, true);
 $ans = curl_exec ($crl);
 $t2=time();
 $lapsed=$t2-$t1;
 echo "<br/>Total time taken" . $lapsed;
 echo $ans;
?>