prototype中的bind方法

<script type="text/javascript" src="prototype_mini.js" ></script>
<script>
	var Cat = Class.create();	
	Cat.prototype = {		
		initialize:function(name){
					this.name = name;		
		},
		show:function(){			alert('show!!!');		}	
	}	

	var Dog = Class.create();	
	
	Dog.prototype = {		
		initialize:function(name){			this.name = name;		},		
		run:function(){			alert("run!!!");		}	
	}		
	
	var cat1 = new Cat("cat1");	
	cat1.show();	
	var dog1 = new Dog();	
	
	run1 = dog1.run.bind(cat1);
	
	run1();
	
	

	show2 = cat1.show.bind(dog1);	
	show2();	
	
	
	function a(a,b){
			alert("a method invoked!!!"+(a+b));	
	}
	function c(){}
	function b(){
			var a = 0;	
	}		
	
	var b1 = new b();	
	a.apply(b1,[1,2]);	//b1继承了a的所有方法和属性
	c.call(b1,1,2);//这样也能调用？
	
</script>