How to add a function to .addTarget from another class.
// in class 1
override func viewDidLoad() {
super.viewDidLoad()
btnGotoVacation.addTarget(MySingletonClass.sharedInstance, action: Selector("visitBodrum:"), forControlEvents:.TouchUpInside)
}
// in class 2
func visitBodrum(sender:AnyObject) {
print("don't forget to visit yalikavak :) ")
}