private void metroButtonLogin_Click(object sender, EventArgs e) { DataSet1TableAdapters.UsersTableAdapter userAda = new DataSet1TableAdapters.UsersTableAdapter(); DataTable dt = userAda.GetDataByUserIDAndPassword(metroTextBoxUser.Text, metroTextBoxPassword.Text); if (dt.Rows.Count > 0) { //login is valid loginFlag = true; UserID = int.Parse(dt.Rows[0]["UserID"].ToString()); MessageBox.Show("Login Successful!"); } else { //login is invalid MessageBox.Show("Invalid Credentials!"); loginFlag = false; return; } Close(); }