var helloButton : NSButton = NSButton()
override func windowDidLoad() {
       
        super.windowDidLoad()

        // Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
        let frame = NSRect(x: 10, y: 10, width: 200, height: 100)
        let button = NSButton(frame: frame)
        button.title = "Click me!"
       
        button.translatesAutoresizingMaskIntoConstraints = false
       
        self.window?.contentView?.addSubview(button)
       
        let horizontalConstraints = NSLayoutConstraint.constraintsWithVisualFormat("|-[button]-|", options: .AlignAllBaseline, metrics: nil, views: ["button":button])
        NSLayoutConstraint.activateConstraints(horizontalConstraints)
       
        let verticalConstraints = NSLayoutConstraint.constraintsWithVisualFormat("V:|-[button]-|", options: .AlignAllBaseline, metrics: nil, views: ["button":button])
        NSLayoutConstraint.activateConstraints(verticalConstraints)
       
        self.helloButton = button
       
    }