Code:
function Person(firstName) {
    var _firstName = firstName;
};

Object.defineProperty(Person, "firstName", {
    get: function() {
        return this._firstName; 
    },
    set: function(value) {
        this._firstName = value;
    },
    configurable: true,
    enumberable: true
});

var p = new Person("John");

console.log(p.firstName); // WHY IS THIS UNDEFINED???
Would appreciate any help anyone can provide. Thanks in advance.