var xmlHttp;

function GetXmlHttpObject( handler ) {
  var objXmlHttp = null;
  if (navigator.userAgent.indexOf("Opera") >= 0) {
    alert ("Opera is not supported i guess... use FF");
    return;
  }
  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;
  }

}