mysql Prepared statement, neither error or data in db
===

I am trying to setup my database handling with prepared statement, but I am kinda stuck. I don't get any error msg to work with and data is not put into the db. I am a little afraid this is just a stupid mistake, but I'd appreciate if you could help me.

I am using php with a mysql database.

Below you can see the function to create a person. getConnection() will open the database connection onto the variable $link and return true if no error occur.

    public function createUser($userName, $password)
    {
		if($this->getConnection() === true) {
			$stmt = mysqli_prepare($this->link, 'INSERT INTO users (Username, Login, Password) VALUES (?, ?, ?)');
			mysqli_stmt_bind_param($stmt, 'sss', $userName, $userName, $password);
			mysqli_stmt_execute($stmt);
			mysqli_stmt_close($stmt);
		}
		$this->link->close();	
	}
If you have an idea, what wrong, I'd be more than happy. I am open to sugestions.

Thanks in advance

/Pyracell