Working in FireFox not IE

[al_se_08]

Hi i have an Ajax script which is working in FireFox but not IE, obviosuly i want a wide range of people to be able to view, but cant seem to figure it out. Any help would be great, here is the code:

	 function LocationClick(e){
	  	 if(e.elementID != null){
			shape = map.GetShapeByID(e.elementID);
			country = shape.GetID()
			if(country == "msftve_1001_200000")
				country = "AUSTRALIA";
                                 ..........
                                 else if (country == "msftve_1001_200017")
				country = "BRAZIL";
			getCountry();
			}
	  	}


                                function getCountry() {
		xhr = new XMLHttpRequest();
		submission = "id="+ country;
		   xhr.open("GET", "tickets.php?" + submission);
		   xhr.onreadystatechange = processNameData;
		   xhr.send(null);
	    }


		function processNameData() {
		if (xhr.readyState == 4) {
			var data = xhr.responseText;
			document.getElementById("ajaxTickets").innerHTML = xhr.responseText;
			}
		else {
			document.getElementById("ajaxTickets").innerHTML = '<img src="images/loading.gif">';
			}
	 	}

Now in IE the loading picture works, but the information is never loaded. Any help would be great
thanks
al