php xml new DOMDocument xml- load main xml xsl new DOMDocument xsl- lo

<?php
$xml = new DOMDocument; 
$xml->load('main.xml'); 
$xsl = new DOMDocument; 
$xsl->load('rss.xsl'); 
$proc = new XSLTProcessor; 
$proc->importStyleSheet($xsl); 

echo $proc->transformToXML($xml);