function addToCartGridAction(productID, available, vendorID, pickup) {	
	var qtyField = $("cartProd_"+productID);
	var isInt = /^-?\d+$/.test(qtyField.value);
	if(!isInt) {
		alert("Quantity is not valid");
		qtyField.focus();
		return false;
	}
	var qty = parseInt(qtyField.value);
	if(qty > available) {
		alert("Quantity is too big");
		qtyField.focus();
		return false;
	}
	
	 $j.ajax({
		   type: "POST",
		   url: "loader.php?modAct=ajax_add_to_cart",
		   data: "vendorID="+vendorID + "&productID= "+ productID + "&qty="+ qty + "&pickup=" + pickup,
		   success: function(msg){
		     eval(msg);
		     qtyField.value = "";
		   }
		 });
	return true;
}				

function checkCartQtyInputEnter(e, productID, available, vendorID, pickup) { //e is event object passed from function invocation
	var characterCode //literal character code will be stored in this variable
	
	if(e && e.which){ //if which property of event object is supported (NN4)
		e = e;
		characterCode = e.which; //character code is contained in NN4's which property
	}
	else{
		e = event
		characterCode = e.keyCode; //character code is contained in IE's keyCode property
	}
	
	if(characterCode == 13){ //if generated character code is equal to ascii 13 (if enter key)
		addToCartGridAction( productID, available, vendorID, pickup);
		//document.forms[0].submit() //submit the form		
		stopEvent(e);
		return false;
	}
	
	return true;
}