function GetXmlHttpObject(handler) {                            //work out which Ajax object to return
  var objXMLHttp=null
  if (window.XMLHttpRequest) {
    objXMLHttp=new XMLHttpRequest()
  } else if (window.ActiveXObject) {
    objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
  }
  return objXMLHttp
}