how to read from a local xml file

hi, i created a new hybrid html5 app, added one xml file under www folder and this code to a button click

but the code binded to onreadystatechange event never get executed. can someone help me to understand what's wrong?

:Thanks.

$(document).on("click", ".uib_w_1", function(evt)
    {
        var path = window.location.href ;
        path = path.substring( 0, path.lastIndexOf('/') ) ;
        var xmlhttp = new XMLHttpRequest();
        var FileName = path + "/test.xml";
        xmlhttp.open("GET", FileName, false);
        xmlhttp.onreadystatechange  = function(){
            if(xmlhttp.readyState==4){
                response = xmlhttp.responseText;
                var doc = new DOMParser().parseFromString(response, "text/xml");
                console.log(doc);
                var nodes = document.evaluate("/items/item/@id",doc, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,null);
                console.log(nodes);
                console.log(nodes.snapshotLength);
                for(var i =0; i<nodes.snapshotLength; i++){
                    thisElement = nodes.snapshotItem(i);
                    console.log(thisElement.nodeName);
                }
            }
        };
    });

xml file contents:

<?xml version="1.0" encoding="utf-8"?>
<items>
  <item id="1" />
  <item id="2" />
  <item id="3" />
</items>