private bool IsValidForm()
        {
            bool areFilled  = FieldValidation.NotNullOrEmpty(FirstNameBox.Text, LastNameBox.Text, WorkExperienceBox.Text);
            bool isSelected = FieldValidation.IsSelected(AccountComboBox.SelectedIndex);

            return(areFilled && isSelected);
        }
 private bool IsValidForm() =>
 FieldValidation.NotNullOrEmpty(NameBox.Text) && FieldValidation.IsSelected(PlaceComboBox.SelectedIndex);
 private bool IsValidForm() =>
 FieldValidation.NotNullOrEmpty(FullNameBox.Text, EmailBox.Text, PasswordBox.Password) && FieldValidation.IsSelected(RolesComboBox.SelectedIndex);