//code used to create an http request object
function createRequest()
{
var request=null;

try
{
     request=new XMLHttpRequest();//creates request for browsers other than microsoft
}catch(trymicrosoft)
{
     try
     {
	request=new ActiveXObject("Msxml2.MXLHTTP"); //creates request for IE 7+
     }catch(othermicrosoft)
      {
	try
           {
	     request=new ActiveXObject("Microsoft.XMLHTTP"); //creates request for IE<7
	   }catch(failed)
            {
	       request=null;
	    }
      }
}
if (request==null)
	alert("Error creating request object!");
else
	return request;
}