AJAX

From CodeMonkeyWiki

function getAjaxObject() {
  var xmlHttp;
  try {
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
  } catch (e) {
    // Internet Explorer
    try {
      xmlHttp=new ActiveXObject('Msxml2.XMLHTTP');
    } catch (e) {
      try {
        xmlHttp=new ActiveXObject('Microsoft.XMLHTTP');
      } catch (e) {
        alert('This browser is not AJAX comaptible');
        return false;
      }
    }
  }
  return xmlHttp;
}

function ajaxFunction() {
  var url = 'service_to_hit';
  var xmlHttp = getAjaxObject();
  if (xmlHttp) {

    xmlHttp.onreadystatechange=function() {

      if (xmlHttp.readyState==4) {
        if (xmlHttp.responseXML) {
          var doc=xmlHttp.responseXML.documentElement;
            // got doc, can do something with the xml
          }
        } // end xml recieved
      } // end readyState = 4
    } // end readyState function
    sendData(xmlHttp, url);
  }
}

function sendData(xmlHttp, url) {
  try {
    xmlHttp.open('GET',url,true);
    xmlHttp.send(null);

  } catch (e) {
    // could not hit url, or other error happened
  }
}