private bool Validate() { var validationResult = UserValidation.Validate( textBox_Create_Login.Text, passwordBox_Create_Password.Password, passwordBox_Create_Password_Copy.Password); if (validationResult.IsValid) { if (_userBusinessComponent.Exists(textBox_Create_Login.Text)) { MessageBox.Show("A user with such username already exists!"); return(false); } return(true); } else { MessageBox.Show(validationResult.Error); return(false); } }