UIImage goes where i tap (But i need it so you can ONLY drag it)

I have a

and I linked it into my code and named it "Person"
At the moment where ever I tap on the screen, the jumps to that position, but I want it so the image can ONLY move if I drag it. Here's my code:

var location = CGPointMake(0, 0)



@IBOutlet var Person: UIImageView!



override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {



    let touch : UITouch = touches.first as UITouch!



    location = touch.locationInView(self.view)



    Person.center = location



}



override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {



    let touch : UITouch = touches.first as UITouch!



    location = touch.locationInView(self.view)



    Person.center = location



}



override func viewDidLoad() {

    super.viewDidLoad()

    // Do any additional setup after loading the view, typically from a nib.



    Person.center = CGPointMake(160, 330)





}