I have the following JavaScript code:

<script language="javascript">
var xmlhttp;
	if (window.XMLHttpRequest) {
		// code for IE7+, Firefox, Chrome, Opera, Safari
		xmlhttp=new XMLHttpRequest();
	} else if (window.ActiveXObject) {
		// code for IE6, IE5
		xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		alert("Your browser does not support XMLHTTP!");

	xmlhttp.open( "GET", "http://www.w3schools.com/xml/plant_catalog.xml", true );   

       xmlhttp.onreadystatechange = function () 
		alert( xmlhttp.responsetext );
In Safari it comes up saying: undefined.

does anyone know why its doing this?

I am running Safari 5.1.2.

Or does anyone know another way of viewing an XML/or, another page client-side, without using php or asp (server-side).