var myUrl;
var ex_type;
var req;

function processResults() {
  if (req.readyState == 4) {
    if (req.status == 200) {
      if (req.responseText) {
        doAction(req.responseText);
      } else if (req.responseXML) {
        //do something with the returned XML data
      }
    } else {
      alert("There was a problem retrieving"
            +"the XML data:\n" + req.statusText);
    }
  }
}

function loadData(url) {
  if (window.XMLHttpRequest) {
    req = new XMLHttpRequest();  //native
    req.onreadystatechange = processResults;
    req.open("GET", url, true);
    req.send(null);
  } else if (window.ActiveXObject) {
    req = new ActiveXObject("Microsoft.XMLHTTP");  //IE/Windows ActiveX version
    if (req) {
      req.onreadystatechange = processResults;
      req.open("GET", url, true);
      req.send(null);
    }
  }
}