func pulseBorderColor() {
    let pulseAnimation = CABasicAnimation(keyPath: "borderColor")
    pulseAnimation.duration = 0.35
    pulseAnimation.fromValue = UIColor.green.cgColor
    pulseAnimation.toValue = UIColor(red: 252/255, green: 180/255, blue: 29/255, alpha: 1.0).cgColor
    pulseAnimation.fillMode = kCAFillModeForwards
    pulseAnimation.isRemovedOnCompletion = false
    pulseAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
    nationalIdentityTextField.layer.sublayers![0].add(pulseAnimation,forKey: nil)
}

func reversePulseBorderColor() {
    let pulseAnimation = CABasicAnimation(keyPath: "borderColor")
    pulseAnimation.duration = 0.35
    pulseAnimation.fromValue = UIColor(red: 252/255, green: 180/255, blue: 29/255, alpha: 1.0).cgColor
    pulseAnimation.toValue = UIColor.green.cgColor
    pulseAnimation.fillMode = kCAFillModeForwards
    pulseAnimation.isRemovedOnCompletion = false
    pulseAnimation.timingFunction = CAMediaTimingFunction(name:  kCAMediaTimingFunctionEaseInEaseOut)
    nationalIdentityTextField.layer.sublayers![0].add(pulseAnimation,forKey: nil)
}