         swipeDownRecognizer.direction = UISwipeGestureRecognizerDirection.Down
         self.view?.addGestureRecognizer(swipeDownRecognizer)
 
-        // Physics - setting gravity to game world
+        // Physics - Setting Gravity to Game World
         self.physicsWorld.gravity = CGVectorMake(0.0, -9.8)
         self.physicsWorld.contactDelegate = self
         
+        // City Background [Tina]
         for var index = 0; index < 2; ++index {
             let bg = SKSpriteNode(imageNamed: "bg\(index).jpg")
             bg.anchorPoint = CGPointZero

        ground.physicsBody?.dynamic = false
        ground.physicsBody?.categoryBitMask = UInt32(self.groundCategory)

        println(self.frame.size.width)
        println(groundTexture.size().height * 2)
        

        self.addChild(ground)
        
    }
    
    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {

    }

    func swipeUpAction(swipe: UISwipeGestureRecognizer) {

        self.jumpMode = true
        self.jumpTime = 0.0
        println(self.jumpNumber)
        println(self.jumpTime)
        println(self.deltaTime)
//         Jump Limit Logic ------ Uncomment to use.
        if self.jumpNumber < 2 && self.jumpTime <= 0.5 {
            self.hero.physicsBody!.velocity = CGVectorMake(0, 0)
            self.hero.physicsBody!.applyImpulse(CGVectorMake(0, 35))
            self.jumpNumber += 1
        }
    }
    
    func swipeDownAction(swipe: UISwipeGestureRecognizer) {
        println("Swipe down")
        let wait = SKAction.waitForDuration(1.0)
        
    }
    
    func didBeginContact(contact: SKPhysicsContact) {
        println("Contact occured")
        self.jumpNumber = 0
    }
    
    override func update(currentTime: CFTimeInterval) {

            self.jumpTime = self.jumpTime + self.deltaTime
        }
    }
    
    // MARK: - HERO ACTIONS
    // [Tuan/Vincent]
    
    func swipeUpAction(swipe: UISwipeGestureRecognizer) {
        
        self.jumpMode = true
        self.jumpTime = 0.0
        println(self.jumpNumber)
        println(self.jumpTime)
        println(self.deltaTime)
        //         Jump Limit Logic ------ Uncomment to use.
        if self.jumpNumber < 2 && self.jumpTime <= 0.5 {
            self.hero.physicsBody!.velocity = CGVectorMake(0, 0)
            self.hero.physicsBody!.applyImpulse(CGVectorMake(0, 35))
            self.jumpNumber += 1
        }
    }
    
    func swipeDownAction(swipe: UISwipeGestureRecognizer) {
        println("Swipe down")
        let wait = SKAction.waitForDuration(1.0)
    }
    
    func didBeginContact(contact: SKPhysicsContact) {
        println("Contact occured")
        self.jumpNumber = 0
    }
    
}
