//calculate the amount
//FOR STUDENT ORDER
function calculateAmount(form, main, dessert, len, mainPrice, dessertPrice, dessertMenuExisted, numOfChoice){
	var value = 0;
	var temp = mainPrice - 0;
	var temp2 = dessertPrice - 0;
	var i;
	for(i=0; i<len; i++){
		if(	form.elements[main+"_"+i].value=="X" ||
			(numOfChoice >= 1 && form.elements[main+"_"+i].value=="A") ||
			(numOfChoice >= 2 && form.elements[main+"_"+i].value=="B") ||
			(numOfChoice >= 3 && form.elements[main+"_"+i].value=="C") ||
			(numOfChoice >= 4 && form.elements[main+"_"+i].value=="D")){
			if(form.elements[main+"_"+i].value!="X")
				value = value + temp;
		}else{
			//alert("Main choice is invalid!");
			alert("主菜選擇不正確!");
			return 0;
		}
		
		if(dessertMenuExisted){
			if(	form.elements[dessert+"_"+i].value=="X" ||
				(numOfChoice >= 1 && form.elements[dessert+"_"+i].value=="A") ||
				(numOfChoice >= 2 && form.elements[dessert+"_"+i].value=="B") ||
				(numOfChoice >= 3 && form.elements[dessert+"_"+i].value=="C") ||
				(numOfChoice >= 4 && form.elements[dessert+"_"+i].value=="D")){
				if(form.elements[dessert+"_"+i].value!="X")
					value = value + temp2;
			}else{
				//alert("Dessert choice is invalid!");
				alert("甜品選擇不正確!");
				return 0;
			}
		}
	}
	
	return Math.round(value*100)/100;
}



function closeWin(){
	this.close();
}




IE4plus = (document.all) ? true : false;
NS4 = (document.layers) ? true : false;

//for right click

function clickIE()
{
    return true;
}

function clickNS(e)
{
	if (e.which==2 || e.which==3) 
     {
       return false;
     }
}
if (!IE4plus) 
{
   document.captureEvents(Event.MOUSEDOWN || Event.MOUSEUP);
   document.onmousedown=clickNS;
   document.onmouseup= clickNS;
   document.oncontextmenu=clickIE; // For NS 6+
} 
else 
{
   document.onmouseup= clickIE;
   document.oncontextmenu=clickIE;
}