function GetXmlHttpObject()
{
  var xmlHttp=null;
  try
  {
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
  }
  catch (e)
  {
    // Internet Explorer
    try
    {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
  }
  
  return xmlHttp;
}