<script language="JavaScript">
function Person(first, last) {
this.init(first, last);
}
Person.prototype.init = function(first, last) {
this.first = first;
this.last = last;
};
Person.prototype.toString = function() {
return this.first + " " + this.last;
}
Employee.prototype = new Person();
Employee.prototype.constructor = Employee;
Employee.superclass = Person.prototype;
function Employee(first, last, id) {
Employee.superclass.init.call(this, first, last);
this.id = id;
}
Employee.prototype.toString = function() {
var name = Employee.superclass.toString.call(this);
return this.id + ": " + name;
}
var person = new Person("Muneeb", "Ahmad");
alert(person);
var employee = new Employee("Kevin", "Johnson", 1001);
alert(employee);
</script>