//Gets the browser specific XmlHttpRequest Object
function getXmlHttpRequestObject() {
	if (window.XMLHttpRequest) {
		return new XMLHttpRequest();
	} else if(window.ActiveXObject) {
		return new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		alert("Old Browser detected, You should consider updgrading!");
	}
}

//Our XmlHttpRequest object to get the auto suggest
var searchReq2 = getXmlHttpRequestObject();

//Starts the AJAX request.
function checkCoupon(code) {

		   
		   if (searchReq2.readyState == 4 || searchReq2.readyState == 0) {
		   if (code != ''){
		   var str2 = escape(document.getElementById('coupon').value);
		   searchReq2.open("GET", 'ajax/check_coupon.php?code=' + str2, true);
		   searchReq2.onreadystatechange = handleCouponDetails; 
		   searchReq2.send(null);
		   }


	}		
}

//Called when the AJAX response is returned.
function handleCouponDetails() {
	if (searchReq2.readyState == 4) {

			var alertmsg = searchReq2.responseText;
			alert(alertmsg);

	}
}