var xmlHttp;

function GetXmlHttpObject() {
	var xmlHttp=null;
	try  {
	 // Firefox, Opera 8.0+, Safari
	 xmlHttp=new XMLHttpRequest();
	 }
	catch (e)  {
	 // Internet Explorer
	 try {
	  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
	  }
	 catch (e)   {
	  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
	  }
	 }
	return xmlHttp;
} // end function

function updatePromos(str, sesskey, st, tax, br, ss, gt ) {
	if (str.length > 2) {		 
		xmlHttp=GetXmlHttpObject();
		if (xmlHttp==null) {
			alert ("Browser does not support HTTP Request");
			return;
		} 
		
		var url="/php/updatepromos.php";
		url=url+"?promo="+str;
		url=url+"&sesskey="+sesskey;
		url=url+"&st="+st;
		url=url+"&tax="+tax;
		url=url+"&br="+br;
		url=url+"&ss="+ss;
		url=url+"&gt="+gt;
		url=url+"&sid="+Math.random();
		xmlHttp.onreadystatechange=stateChangedPromos;
		xmlHttp.open("GET",url,true);
		xmlHttp.send(null);
	} // end if

	if (str.length==0) { 
	 document.getElementById("promos").style.border="0px";
	 return;
	} // end if
	
	updatePrices( st, tax, br, ss, gt);
} // end function

function stateChangedPromos() { 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")  { 
		 document.getElementById("promo_price").innerHTML=xmlHttp.responseText;
	 } // end if
} // end function

function updatePrices( st, tax, br, ss, gt ) {
		 if (tax > 0) { 
		 	tax = ((st - 12) * 0.09);
		 } else {
		 	tax = 0;
		 } // end else
		 gt = (st - 12) + tax + 8.5 + ss;
		 gt = (gt - br);
		 document.getElementById("tax").innerHTML=tax;
		 document.getElementById("GrandTotal").innerHTML=gt;
} // end function