[jQuery] Server side JQeury

[jQuery] Server side JQeury


I have been following John's article: http://ejohn.org/blog/bringing-the-browser-to-the-server
The script only support well formed XML, as defined in the function
(env.js)
window.__defineSetter__("location", function(url){
        var xhr = new XMLHttpRequest();
        xhr.open("GET", url);
        xhr.onreadystatechange = function(){
            curLocation = new java.net.URL( curLocation, url );
            window.document = xhr.responseXML;
            var event = document.createEvent();
            event.initEvent("load");
            window.dispatchEvent( event );
        };
        xhr.send();
    });
But why we need fetch valid XML?