I have been searching around for the code to be able to do the same thing, but one is for iPhones and another for iPads. I am using swift,

I have been searching around for the code to be able to do the same thing, but one is for iPhones and another for iPads. I am using swift, and the following code is not doing what it is suppose to do. Could anyone answer why?

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?




    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

        func grabStoryboard() -> UIStoryboard {
            var storyboard = UIStoryboard()
            var height = UIScreen.mainScreen().bounds.size.height

            if height == 480/568/667/736{
                storyboard = UIStoryboard(name: "iPhone", bundle: nil)
            } else {
                if height == 768{
                    storyboard = UIStoryboard(name: "iPad", bundle: nil)
                }
            }
            return storyboard
        }

Thank You all in advanced!