I am getting an error in Xcode 8.

import UIKit
class ViewController: UIViewController {

    @IBOutlet weak var nameTextBox: UITextField!

    @IBOutlet weak var firstQuestion: UILabel!

    @IBAction func nextButton() {
        if nameTextBox.text != nil {
            let name = nameTextBox.text
            firstQuestion.text = name
        }
        else {
            print("Wrong!")
        }
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

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