function SendAjax(url, callbackFunction) {
   if (window.XMLHttpRequest) {
      var request = new XMLHttpRequest();
   } else {
      var request = new ActiveXObject("Microsoft.XMLHTTP");
   }
 
   request.open("POST", url, true);
   request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
 
   request.onreadystatechange = function() {
      if (request.readyState == 4 && request.status == 200) {
         if (request.responseText) {
            ReceiveAjax(request.responseText, callbackFunction);
         }
      }
   }

   request.send(null);
}

function ReceiveAjax(response, callbackFunction) {
   if (window.ActiveXObject) {
      var doc = new ActiveXObject("Microsoft.XMLDOM");
      doc.async = "false";
      doc.loadXML(response);
   } else {
      var parser = new DOMParser();
      var doc = parser.parseFromString(response,"text/xml");
   }
   callbackFunction(doc.documentElement);
}

function ValueFromTagName(item, tagname) {
   var val = item.getElementsByTagName(tagname);
   return val[0].firstChild.nodeValue;
}