<?php 
$gelenveri = "http://www.reklam.swf";

$sonbirharf =  substr($gelenveri , -1); 

$reklam = file_get_contents("http://localhost/a.xml"); 
$a = "$sonbirharf";
$zimbala = str_replace($sonbirharf,"$sonbirharf\n$reklam",$gelenveri); 
$pompala = $zimbala; 
echo "$pompala"; 
?>