stest/public/css/demo/demo.js

var totalPrice = 0;

function addGoods(price)
{
	totalPrice = addPrice(totalPrice, price);
	
	getPrice(totalPrice);
}


function getPrice(price)
{
	var f = parseFloat(price); 
	 
	if (isNaN(f)) 
	{    
		return false;    
	}    
	
	var f = Math.round(price*100)/100;    
	var s = f.toString();    
	var rs = s.indexOf('.');    
	if (rs < 0) 
	{    
		rs = s.length;    
		s += '.';    
	}    
	while (s.length <= rs + 2) 
	{    
		s += '0';    
	} 

	document.getElementById('MM-Price-span').innerText='$'+s;
}

function addPrice(arg1,arg2)
{
   return parseInt(arg1)+parseInt(arg2);
}