Hi guys, Im getting this error when using php 5.3:

Code:
Deprecated: Function ereg_replace() is deprecated in etc.........
When I remove the following section of code from my file the error goes away. I know "ereg_replace()" is deprecated as of php version 5.3, but the confusing part is im not using "ereg_replace()" anywhere. As you can see from the code below its not being used. Any ideas what could be wrong ?

PHP Code:
$baseurl="http://".$_SERVER['HTTP_HOST'];
$pos = strtolower($baseurl);
$url2 = @parse_url($pos); 
$url3 = $url2['host']; 
$url=str_replace("www.","",$url3);

$sites = strtolower(HOST);
$sites2 = @parse_url($sites); 
$sites3 = $sites2['host']; 
$baseurlfinal=str_replace("www.","",$sites3);

if($url==$baseurlfinal) {
$md5=md5(md5($baseurlfinal));
$sh1=sha1($baseurlfinal);
$string=$sh1.$md5;
$key=substr($string, 45);
$keyfinal=strrev("$key");