function Person(name, age, email){
	this.name = name;
	this.age = age;
	this._email = email;
}

function _Person_show_me(){
	alert('我叫' + this.name + '，我' + this.age + '岁了，我的email是' + this._email);
}

Person.prototype.show_me = _Person_show_me;

function Student(name, age, email, score){
	Person.call(this, name, age, email);
	this.score = score;
}

function _Student_show_score(){
	alert("我的分数是：" + this.score);
}

Student.prototype = new Person();
Student.prototype.show_score = _Student_show_score;

var he = new Student('小何', 28, 'baijun.he@163.com', 80);
he.show_me();
he.show_score();