private bool CloseKeyboard(UITextField textField)
 {
     if (textField.Equals(txtSubject))
     {
         // validate field inputs as per your requirement
         txtDescription.BecomeFirstResponder();
         return true;
     }
     if (textField.Equals(txtDescription))
     {
         // validate field inputs as per your requirement
         textField.ResignFirstResponder();
         return true;
     }
     return true;
 }
 private bool CloseKeyboard(UITextField textField)
 {
     if (textField.Equals(txtComment))
     {
         // validate field inputs as per your requirement
         textField.ResignFirstResponder();
         return true;
     }
     return true;
 }