var request = null;
var request2 = null;
var request3 = null;
var request4 = null;
try {
  request = new XMLHttpRequest();
  request2 = new XMLHttpRequest();
  request3 = new XMLHttpRequest();
  request4 = new XMLHttpRequest();  
} catch (trymicrosoft) {
  try {
    request = new ActiveXObject("Msxml2.XMLHTTP");
	request2 = new ActiveXObject("Msxml2.XMLHTTP");
	request3 = new ActiveXObject("Msxml2.XMLHTTP");
	request4 = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (othermicrosoft) {
    try {
      request = new ActiveXObject("Microsoft.XMLHTTP");
	  request2 = new ActiveXObject("Microsoft.XMLHTTP");
	  request3 = new ActiveXObject("Microsoft.XMLHTTP");
	  request4 = new ActiveXObject("Microsoft.XMLHTTP");
    } catch (failed) {
      request = null;
	  request2 = null;
	  request3 = null;
	  request4 = null;
    }
  }
}

if (request == null)
  alert("Error creating request object!");

if (request2 == null)
  alert("Error creating request2 object!");
  
if (request3 == null)
  alert("Error creating request3 object!");
  
if (request4 == null)
  alert("Error creating request3 object!");