astupidname - 8:21 am on Nov 30, 2011 (gmt 0)

You are so going to kick yourself

Umm, yeah all of you will! :-)
After you correctly fix the second title tag to a closing </title>, then in your php file this:

file_get_contents('http://'.sanitizeString($_GET['url']));

should be:

echo file_get_contents('http://'.sanitizeString($_GET['url']));

(Actually, according to the title of this thread, I should have instead told you to remove this:

<h2>Loading a XML content into a DIV</h2>

:-)