JavaScriptのオブジェクトの深さクローン

Object.prototype.clone = function() {
		var newObj = {};
		for(var i in this) {
			if(typeof(this[i]) == "object" || typeof(this[i]) == "function") {
				newObj[i] = this[i].clone();
			}
			else {
				newObj[i] = this[i];
			}
		}
		return newObj;
	};

	Array.prototype.clone = function() {
		var newArray = [];
		for(var i = 0; i < this.length; i++) {
			if(typeof(this[i]) == "object" || typeof(this[i]) == "function") {
				newArray[i] = this[i].clone();
			}
			else {
				newArray[i] = this[i];
			}
		}
		return newArray;
	};

	Function.prototype.clone = function() {
		var that = this;
		var newFunc = function() {
			return that.apply(this, arguments);
		};
		for(var i in this) {
			newFunc[i] = this[i];
		}
		return newFunc;
	};

	function Owner(name) {
		this.name = name;
	}

	function Car(owner, brand) {
		this.owner = owner;
		this.brand = brand;
		this.drive = function() {
			alert(this.owner.name + "  " + brand + "  ");
		};
	}

	var o = new Owner("Hao");
	var c1 = new Car(o, "Benz");

	c1.drive();

	var c2 = c1.clone();
	c2.owner.name = "Wang";

	c1.drive();