... load a file?

jQuery.ajax({
            type:"GET",
            url:this.file,
            dataType:"xml",
            success:function(xml){alert(xml);}
            }); 

jQuery.get("test.xml",function(xml){alert(xml);});

instanceProto.loadFile = function(file)
    {
        var request = null;
        if (window.XMLHttpRequest) 
        {
            request = new XMLHttpRequest;
        }
        else
        {
            alert("XMLHttpRequest is not supported by your browser.");
        };
        
        if(!(request === null))
        {
            request.open("GET", file, true);
            request.onreadystatechange = function()
            {
                if (request.readyState == 4 /* complete */) {
                    if (request.status == 200 || request.status == 304) {
                    alert('Transfer complete. XML data updated.');
                    this.data = request.responseText;
                    this.ready = true;
                }
                else {
                    alert('An error occurred. Old XML data kept.');
                    this.ready = true;
                };
            };
            request.send();
            this.ready = false;
            };
        }
        
    }