$extend(subClass,superClass)

gistfile1.txt

        var Human = function(name){
            this.name = name;
            this.isAlive = true;
            this.energy = 1; 
        };

        Human.prototype.eat = function() {
            return this.energy++;
        };
 
        var Gibon = function(name) {
            Gibon._base.call(this,name);  
            this.kills = 0;
        };

        GIB.extend(Gibon, Human);

        Gibon.prototype.attack = function(target) {
              target.isAlive = false;
              this.kills++;
        };

        Gibon.prototype.eat = function() {
              Gibon._super.eat.call(this);
              return this.energy +=2;
        };
 
        var h = new Human('adrian');
        var g = new Gibon("croco");
            g.eat();
            g.attack(h);
            alert("g energy:" + g.energy);
            //->4      
            alert("h isAlive: " + h.isAlive);
            //->false
            alert("g isAlive: " + g.isAlive);
            //->true