```
var setAge = function (newAge) {
  this.age = newAge;
};
// now we make bob
var bob = new Object();
bob.age = 30;
bob.setAge = setAge;
bob.setAge(50);
console.log(bob.age);

```

This works, but when I try to do this

```
var setAge = function (newAge) {
  this.age = newAge;
};
var bob = new Object();
bob.age = 30;
bob.setAge(50);
console.log(bob.age);

```

it returns "bob.setAge() is not a function" in the compiler?