6-7.html

<!DOCTYPE html>
<script>
	function inherit(C, P){
		var F = function(){};
		F.prototype = P.prototype;
		C.prototype = new F();
	}

	function Parent(name){
		this.name = name;
	}
	Parent.prototype.say = function(){
		return this.name;
	};

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

	inherit(Child, Parent);

	var kid = new Child();
	alert(kid.name); // undefined

	var kid2 = new Child('hoge');
	alert(kid2.say()); // hoge 

</script>