var name;
var age;

function Person(myName, myAge) {
this.getName = function() { return name; }
this.getAge = function() { return age; }

this.setName = function(value) { name = value; }
this.setAge = function(value) { age = value; }

name = myName;
age = myAge;

}

var person0 = new Person("João", 54);
var person1 = new Person("Maria", 62)

person0.setName( person0.getName() + ' Félix');

alert(name);
alert(person0.getName());
alert(person1.getAge());