function GetXmlHttpObject()
{
  var objXMLHttp=null
  
  try {
    objXMLHttp = new ActiveXObject("Msxml2.XMLHTTP"); //later IE
  } catch (e) {
  try {
    objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP"); //earlier IE
  } catch (e) {
  objXMLHttp = null;
  }
  }
  
  if (objXMLHttp==null)
  {
    objXMLHttp=new XMLHttpRequest() //IE7, Firefox, Safari
  }
  return objXMLHttp
}