var http_request = false;
function makeRequest(serial) {
	http_request = false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
        	if (http_request.overrideMimeType) {
            		http_request.overrideMimeType('text/html');
         	}
      		} else if (window.ActiveXObject) { // IE
         		try {
            			http_request = new ActiveXObject("Msxml2.XMLHTTP");
         		} catch (e) {
            			try {
               				http_request = new ActiveXObject("Microsoft.XMLHTTP");
            			} catch (e) {}
       		}
    	}
    	if (!http_request) {
        	alert('Cannot create XMLHTTP instance');
         	return false;
      	}
//       	http_request.onreadystatechange = function(){
// 		if (http_request.readyState == 4 && http_request.status == 200) {
//         	var recdoc = http_request.responseText;	
// 		response=unserialize(recdoc);
// 		
// 		var finalResponse=response;
// 		} 
// 	};
	http_request.onreadystatechange = alertContents;
      	http_request.open('GET', "./src/checkSerial.php?serial="+serial, true);
      	http_request.send(null);
	
}

function alertContents(){
	if (http_request.readyState == 4 && http_request.status == 200) {
        	var recdoc = http_request.responseText;	
		document.getElementById('couponDisplay').style.display="block";
		document.getElementById('couponDisplay').innerHTML=recdoc;		
		document.getElementById('image_loader').src = "images/arrow2.png";

		//*****XXXXXX   update backorder link, kill this line when stock is back in   XXXXX*****//
		//document.getElementById('shoplink').href = document.getElementById('shoplink').href+"?Coupon="+recdoc+"&Serial="+document.getElementById('serialNum');
		
	} 

}
function checkSerial(){	
	var serial="";
	serial=document.getElementById('serialNum').value;
	document.getElementById('image_loader').src = "images/ajax-loader.gif";
	
	return makeRequest(serial);
}