expected declaration after if statement

I have an "expected declaration" at this line:

if(userEmail.isEmpty || userPassword.isEmpty || userRepeatPassword.isEmpty)

Could you tell me why? Thank you in advance.

My code:

class RegisterPageViewController: UIViewController {

@IBOutlet weak var userEmailTextField: UITextField!
@IBOutlet weak var userPasswordTextField: UITextField!
@IBOutlet weak var repeatPasswordTextField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func registerButtonTapped(_ sender: AnyObject) {

    let userEmail = userEmailTextField.text;
    let userPassword = userPasswordTextField.text;
    let userRepeatPassword  = repeatPasswordTextField.text
}

// Check for empty fields

if(userEmail.isEmpty || userPassword.isEmpty || userRepeatPassword.isEmpty)
{

// Display Alert Message
displayMyAlertMessage("All fields are required");
return;

}