private void SignIn_Click(object sender, EventArgs e)
        {
            Admin admin = new Admin();

            admin.Username = usernametf.Text;
            admin.Password = passwordtf.Text;
            string err;

            if (repo.CheckAdmin(admin, out err))
            {
                this.Visible = false;
                Form2 a = new Form2();
                a.Visible = true;
            }
            else
            {
                MessageBox.Show("wrong or missing info ");
            }
        }