data.chinahighlights.com/js/product-calculator.js

// Abstract PriceCalculator
var AbstractPriceCalculator = function (){};
AbstractPriceCalculator.prototype = {
    calculation_price : function(){}
}

// Adults Price Calculator
var AdultsPriceCalculator = function(){};
AdultsPriceCalculator.prototype = new AbstractPriceCalculator();
AdultsPriceCalculator.prototype.calculation_price = function(Num, Price){
    return Num * Price;
};

// Children Price Calculator
var ChildrenPriceCalculator = function(){}
ChildrenPriceCalculator.prototype = new AbstractPriceCalculator();
ChildrenPriceCalculator.prototype.calculation_price = function(Num, Price){
    return Num * (Price * 0.75);
};

// Babies Price Calculator
var BabiesPriceCalculator = function(){};
BabiesPriceCalculator.prototype = new AbstractPriceCalculator();
BabiesPriceCalculator.prototype.calculation_price = function(Num, Price){
    return Num * (Price * 0.10);
};



// Abstract Price Difference
var AbstractPriceDifference = function(){
	 //this.init.apply(this,arguments);
};
AbstractPriceDifference.prototype = {
    number_people : 0,
    price : 0,
	extra : 0,
    calculation_price : function(){}
};

var OddPriceDifference = function(){};
OddPriceDifference.prototype = new AbstractPriceDifference(); 
OddPriceDifference.prototype.calculation_price = function(ObjPriceCalculator){
    var temp_price = 0;
	var temp_Difference_price = 1 * this.price * 1.75;
	if (this.number_people > 0){
		if (this.number_people - this.extra > 0){
			temp_price = ObjPriceCalculator.calculation_price((this.number_people - this.extra) * 2, this.price) + temp_Difference_price;
		}else{
			temp_price = this.number_people * temp_Difference_price;
		}
	}
    return temp_price;
};

var EvenPriceDifference = function(){};
EvenPriceDifference.prototype = new AbstractPriceDifference(); 
EvenPriceDifference.prototype.calculation_price = function(ObjPriceCalculator){
    var temp_price = 0;
    temp_price = ObjPriceCalculator.calculation_price(this.number_people, this.price);
    return temp_price;
};

//Abstract Product Manager
var AbstractProductManager = function(){};
AbstractProductManager.prototype = {
	adults_people   : 0,
	children_people : 0, 
	babies_people   : 0,
    price : 0,
	extra : 0,
    calculation_price : function(){}
};
var CruiseProductManager = function(){};
CruiseProductManager.prototype = new AbstractProductManager();
CruiseProductManager.prototype.calculation_price = function(ObjAbstractPriceDifference_array, ObjAbstractPriceCalculator_array){
	
	var obj_price_difference = null;
	var adults_price = 0, children_price = 0, babies_price = 0, total_prices = 0;
	var selectType = 0;
	selectType = (this.adults_people + this.children_people + this.babies_people) / 2 ;
	if (this.extra <= selectType) {
		obj_price_difference = ObjAbstractPriceDifference_array[0];
		obj_price_difference.price = this.price;
		obj_price_difference.number_people = this.adults_people;
		adults_price   = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[0]);
		obj_price_difference.number_people = this.children_people;
		children_price = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[1]);
		obj_price_difference.number_people = this.babies_people;
		babies_price   = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[2]);
		total_prices   = adults_price + children_price + babies_price;
		
	}else if(this.extra > selectType) {
		obj_price_difference = ObjAbstractPriceDifference_array[1];
		obj_price_difference.price = this.price;
		obj_price_difference.extra         = this.extra;
		obj_price_difference.number_people = this.adults_people;
		adults_price   = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[0]);
		obj_price_difference.number_people = this.children_people;
		children_price = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[1]);
		//alert(children_price);
		obj_price_difference.number_people = this.babies_people;
		babies_price   = obj_price_difference.calculation_price(ObjAbstractPriceCalculator_array[2]);
		total_prices   = adults_price + children_price + babies_price;
	}
	ObjAbstractPriceDifference_array[0] = null;
	ObjAbstractPriceDifference_array[1] = null;
	ObjAbstractPriceCalculator_array[0] = null;
	ObjAbstractPriceCalculator_array[1] = null;
	ObjAbstractPriceCalculator_array[2] = null;
	return total_prices;
};

var PackageProductManager = function(){};
PackageProductManager.prototype = new AbstractProductManager();
PackageProductManager.prototype.calculation_price = function(ObjAbstractPriceCalculator_array){
	var adults_price = 0, children_price = 0, babies_price = 0, total_prices = 0;
	adults_price   = ObjAbstractPriceCalculator_array[0].calculation_price(this.adults_people, this.price);
	children_price = ObjAbstractPriceCalculator_array[1].calculation_price(this.children_people, this.price);
	babies_price   = ObjAbstractPriceCalculator_array[2].calculation_price(this.babies_people, this.price);
	total_prices   = adults_price + children_price + babies_price;
	ObjAbstractPriceCalculator_array[0] = null;
	ObjAbstractPriceCalculator_array[1] = null;
	ObjAbstractPriceCalculator_array[2] = null;
	return total_prices;
};