// ==================================================================================
// project:    Any project that uses AJAX (Asynchronous JavaScript And XML) functions
// file:       Ajax.js
//
// reference:  http://www.w3schools.com/ajax/default.asp
//
// modified:
//
// - xmlHttp.readyState
//     0: the request is not initialized
//     1: the request has been set up
//     2: the request has been setn
//     3: the request is in process
//     4: the request is complete
//
// - xmlHttp.open(param1, param2, param3)
//     param1: which method to use when sending the request (GET or POST)
//     param2: URL of the server-side script
//     param3: the request should be handled asynchronously (true or false)
//
// ==================================================================================

function GetXmlHttpObject() {
  var xmlHttp = null;
  try {
    xmlHttp = new XMLHttpRequest();  // Firefox, Opera 8.0+, Safari, Internet Explorer 7.0+
  } catch (e) { // Internet Explorer
    try {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");  // Internet Explorer 6.0+
    } catch (e) {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");  // Internet Explorer 5.5+
    }
  }
  return xmlHttp;
}