function moins(id, cmp){
	if(document.getElementById("qty_"+cmp).value > 1){
		document.getElementById("qty_"+cmp).value--;
		updateUnitPrice(id, cmp);
		updateSubtotal();
	}
}

function plus(id, cmp){
	document.getElementById("qty_"+cmp).value++;
	updateUnitPrice(id, cmp);
	updateSubtotal();
}

function updateUnitPrice(id, cmp){
	var url_default="http://www.xaissbike.com/";
	var qty=parseInt(document.getElementById("qty_"+cmp).value);
	if(qty > 0){
		var xhr=getXhr();
		xhr.onreadystatechange=function(){
			if(xhr.readyState==4 && (xhr.status==200 || xhr.status==0)){
				document.getElementById("totalPrice_"+cmp).innerHTML=xhr.responseText;
			}
		}
		var price=parseFloat(document.getElementById("unitPrice_"+cmp).innerHTML);
		xhr.open("GET",url_default+"pages/updateUnitPrice.php?id="+id+"&qty="+qty+"&price="+price,true);
		xhr.send(null);
	}
	else{
		document.getElementById("qty_"+cmp).value=1;
		updateUnitPrice(id,cmp);
	}
	updateSubtotal();
}

function updateSubtotal(){
	var url_default="http://www.xaissbike.com/";
	var xhr=getXhr();
	xhr.onreadystatechange=function(){
	if(xhr.readyState==4 && (xhr.status==200 || xhr.status==0)){
		document.getElementById("subtotal").innerHTML=xhr.responseText;
		}
	}
	var port=parseFloat(document.getElementById("port").innerHTML);
	xhr.open("GET",url_default+"pages/updateSubtotal.php?port="+port,true);
	xhr.send(null);	
}

function updateCPromo(){
	var url_default="http://www.xaissbike.com/";
	var xhr=getXhr();
	xhr.onreadystatechange=function(){
	if(xhr.readyState==4 && (xhr.status==200 || xhr.status==0)){
		updateSubtotal();
		document.getElementById("cPromoStatus").innerHTML=xhr.responseText;
		}
	}
	var code=encodeURIComponent(document.getElementById("cPromo").value);
	xhr.open("GET",url_default+"pages/updateCPromo.php?code="+code,true);
	xhr.send(null);	
}