private void login_BT_Click(object sender, EventArgs e) { MY_DB db = new MY_DB(); Check_in_out ck = new Check_in_out(); SqlDataAdapter da = new SqlDataAdapter(); DataTable dt = new DataTable(); SqlCommand com = new SqlCommand("SELECT * FROM Accounts, Employees, EmployeeAccounts WHERE username=@user AND password=@pass AND Accounts.acc_id = EmployeeAccounts.acc_id AND Employees.emp_id = EmployeeAccounts.emp_id", db.getConnection); if (radioManager.Checked) { com.CommandText += " AND (title='Manager' OR title = 'Admin')"; } else if (radioEmp.Checked) { com.CommandText += " AND (title='Receptionist' OR title='Janitor')"; } com.Parameters.Add("@user", SqlDbType.VarChar).Value = username_TB.Text; com.Parameters.Add("@pass", SqlDbType.VarChar).Value = password_TB.Text; da.SelectCommand = com; da.Fill(dt); if (dt.Rows.Count > 0) { MessageBox.Show("Login Successful"); this.DialogResult = DialogResult.OK; } else { MessageBox.Show("Invalid Username Or Password", "Login Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } }