var totalCost = 0;
var items = new Array();
var prices = new Array();

var i = 0;
function addItems(itemId, itemAmount, itemPrice) {
	
	itemAmount = itemAmount.substr(0, 2);
	if (parseInt(itemAmount) && parseInt(itemAmount) > -1) {
		items[itemId] = parseInt(itemAmount);
		prices[itemId] = parseFloat(itemPrice);
		if ($(itemId)) {
			$(itemId).value = items[itemId];
	
		}
	} else {
		items[itemId] = 0;
		prices[itemId] = parseFloat(itemPrice);
		if ($(itemId)) {
			$(itemId).value = "";
		}
	}
	
	calculateTotalCost();
	//document.getElementById('totalCost').innerHTML = "Total Cost: $" + totalCost;
	$('totalCost').innerHTML = "Total Cost: $" + totalCost;
}

function calculateTotalCost() {
  
	totalCost = 0;
	for (var key in items) {
		if(items[key]>0 && prices[key]>0){
			totalCost += items[key] * prices[key];
		}
		
	}
	
	if(isNaN(totalCost)){
    totalCost = 0;
  }
  //totalCost = parseInt(totalCost);
	
	if (totalCost != 0) {
		totalCost = Math.round(totalCost * 100) / 100;
		totalCost = totalCost.toFixed(2);		
	} else{
		totalCost = totalCost.toFixed(2);
	}
}

function increase(itemId,itemPrice){
	
	if(isNaN(parseInt($(itemId).value))){
		value = 0;
	}else{
		value = parseInt($(itemId).value);
	}
	$(itemId).value = value + 1;
	addItems(itemId, $(itemId).value, itemPrice);
}

function decrease(itemId,itemPrice){
	
	if(isNaN(parseInt($(itemId).value))){
		value = 0;
	}else{
		value = parseInt($(itemId).value);
	}
	if(value > 1){
		$(itemId).value = value - 1;
	}else{
		$(itemId).value = '';
	}
	
	addItems(itemId, $(itemId).value, itemPrice);
}