Change Header URL

I found how to do it:

http://www.expertzzz.com/forumz/?action=goto&forum_id=2#action=goto&topic_id=11936

change the url of logo in inc/design.inc.php

function getMainLogo()
{
global $dir;
global $site;

$ret = '';

foreach( array( 'gif', 'jpg', 'png' ) as $ext )
if( file_exists( $dir['mediaImages']."logo.$ext" ) )
{
$ret .= '<a href="' . $site['url'] . '">';
$ret .= "<img src=\"{$site['mediaImages']}logo.$ext\" class=\"mainLogo\" alt=\"logo\" />";
$ret .= '</a>';
break;
}
return $ret;
}
change

' . $site['url'] . '
to:
http://www.site.com