var request = null;
try
{
	request = new XMLHttpRequest();
}
catch(trymicrosoft)
{
	try
	{
		request = new ActiveXObject("Msxm12.XMLHTTP");
	}
	catch(othermicrosoft)
	{
		try
		{
			request = new ActiveXObject("Microsoft.XMLHTTP");
		}
		catch(failed)
		{
			request = null;
		}
	}
}
if(request == null)
{
	alert ("error");
}