private void ShowNewCategoryDialog()
{
NewCategoryForm form = new NewCategoryForm();
form.FormClosed += form_FormClosed;
form.Show();
}
private void ShowEditCategoryDialog()
{
NewCategoryForm form = new NewCategoryForm(int.Parse(lstCategory.SelectedValue.ToString()));
form.FormClosed += form_FormClosed;
form.Show();
}