function GetXmlHttpObject(handler){ 
  var objXmlHttp=null

  if (navigator.userAgent.indexOf("MSIE")>=0){ 
    var strName="Msxml2.XMLHTTP"
    if (navigator.appVersion.indexOf("MSIE 5.5")>=0){
      strName="Microsoft.XMLHTTP"
    } 
    try{ 
      objXmlHttp=new ActiveXObject(strName)
      objXmlHttp.onreadystatechange=handler 
      return objXmlHttp
    } 
    catch(e){ 
      alert("Error. Scripting for ActiveX might be disabled") 
      return 
    } 
  } 
  if (navigator.userAgent.indexOf("Mozilla")>=0){
    objXmlHttp=new XMLHttpRequest()
    objXmlHttp.onload=handler
    objXmlHttp.onerror=handler 
    return objXmlHttp
  }
}