Swift If语句不适用于UILabel

我的if语句未显示我想要的内容。有人可以帮忙吗？我想在UILabel中显示一些文本，该文本将根据天气情况确定，随机数小于或等于50。

这是代码。IF语句位于末尾。

import UIKit
import AVFoundation

class ViewController: UIViewController {

var pianoSound = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("two_tone_nav", ofType: "mp3")!)
var audioPlayer = AVAudioPlayer()

override func viewDidLoad() {
    super.viewDidLoad()

    audioPlayer = AVAudioPlayer(contentsOfURL: pianoSound, error: nil)
    audioPlayer.prepareToPlay()
            // 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.
}

@IBOutlet weak var Number: UILabel!
@IBOutlet weak var BA50: UILabel!

@IBAction func Generate(sender: AnyObject) {

           audioPlayer.play()

    var Generate = Int(arc4random_uniform(100))
    Number.text = String(Generate)


    func AboveBelow50(){
        if Generate>=50 {
        self.BA50.text = "No"
    }
        else {
    self.BA50.text = "Yes"
    }

    }
}
}