newbie question re: nodejs and cryto

```
var crypto = require('crypto');

var User = {
  user1: { name: 'bob', salt: 'randomSalt', password: sha1('mypass', this.salt) }
};

function sha1(pass, salt) {
  return crypto.createHmac('sha1', salt).update(pass).digest('hex');
}

```

Why do I have
`console.log(User.user1.password == sha1('mypass', 'randomSalt') //false` ?