void performValidation(bool isValid,string message){
if (!isValid){
this.hasError = true;
this.errorMessage = message;
this.errorLabel.Text = this.errorMessage;
this.labelTextColor = kDefaultErrorColor;
this.errorLabel.TextColor = this.kDefaultErrorColor;
this.activeBorder.BackgroundColor = kDefaultErrorColor;
this.SetNeedsDisplay ();
}else {
this.hasError = false;
this.errorMessage = null;
this.errorLabel.Text = this.errorMessage;
this.labelTextColor = kDefaultActiveColor;
this.activeBorder.BackgroundColor = kDefaultActiveColor;
this.SetNeedsDisplay();
}
}