// new code
var request = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("MSXML2.XMLHTTP.3.0");

function checkVoucherCode(code) {
	var url="/ajax_check_voucher.php?code=" + code;
	
	if(code.length == 6)
		ajax(url, null, stateChangedCode);
}

function stateChangedCode(){
	if (request.readyState==1){
		document.getElementById("choose_gift").innerHTML="";
	} else if (request.readyState == 4) {
		try {
			if(request.status == 200) {
				if (request.responseText){
					document.getElementById("choose_gift").innerHTML=request.responseText;
				}
			}
		}
		catch(e) { }
	}
}

function ajax(url, vars, callbackFunction){
	// for some reason using post and uncommenting the line below doesn't work
        request.open("GET", url, false);
        //request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
 
        request.onreadystatechange = callbackFunction;
        //request.onload=callbackFunction;
        //request.onerror=callbackFunction;
        
        try { request.send(vars); }
	catch(e) { }
}