function getXmlHttpObject() {
  try{ return new XMLHttpRequest() } catch(e) {}
  try{ return new ActiveXObject("MSXML3.XMLHTTP") }catch(e){}
  try{ return new ActiveXObject("MSXML2.XMLHTTP.3.0") }catch(e){}
  try{ return new ActiveXObject("Msxml2.XMLHTTP") }catch(e){}
  try{ return new ActiveXObject("Microsoft.XMLHTTP") }catch(e){}
  return null;
}