Function.prototype.after=function(fn){
    var self=this;
    return function(){
        var ret=self.apply(this,arguments);
        if(ret==='nextSuccessor'){
            return fn.apply(this,arguments);
        }

        return ret;
    }
};


var order=order500yuan.after(order200yuan).after(orderNormal);

order(1,true,500);
order(1,false,500);