//method to call stored procedure to authenticate cashier

        private void LOGIN_BUTTON_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(cs))
            {
                //validation

                if (ID_TXT.Text == "")
                {
                    MessageBox.Show("Please Enter ID");
                }
                if (PASSWORD_TXT.Text == "")
                {
                    MessageBox.Show("Please Enter Password");
                }
                else
                {
                    DataTable      dt = new DataTable();
                    SqlDataAdapter da = new SqlDataAdapter();

                    //paramertised query with stored procedure

                    da.SelectCommand = new SqlCommand("LoginCashier", con);
                    da.SelectCommand.Parameters.AddWithValue("@id", ID_TXT.Text);
                    da.SelectCommand.Parameters.AddWithValue("@password", PASSWORD_TXT.Text);
                    da.SelectCommand.CommandType = CommandType.StoredProcedure;

                    try
                    {
                        da.Fill(dt);
                        if (dt.Rows.Count == 1)
                        {
                            MessageBox.Show("Welcome " + dt.Rows[0].ItemArray[1].ToString());

                            Cashier cu = new Cashier();
                            Cashier.cashier_Id = ID_TXT.Text.ToString();
                            this.Hide();
                            cu.Show();
                        }

                        else
                        {
                            MessageBox.Show("Check your userid and password");
                            ID_TXT.Text       = "";
                            PASSWORD_TXT.Text = "";
                        }
                    }
                    catch (Exception Ex)
                    {
                        MessageBox.Show(Ex.Message.ToString());
                    }
                }
            }
        }
        private void LOGIN_BUTTON_Click(object sender, EventArgs e)
        {
            using (SqlConnection con = new SqlConnection(cs))
            {
                string         query = "Select  * from Cashier where cashier_id = @cashier_id and cashier_pass=@cashier_pass";
                DataTable      dt    = new DataTable();
                SqlDataAdapter da    = new SqlDataAdapter();
                da.SelectCommand = new SqlCommand(query, con);
                da.SelectCommand.Parameters.AddWithValue("@cashier_id", ID_TXT.Text);
                da.SelectCommand.Parameters.AddWithValue("@cashier_pass", PASSWORD_TXT.Text);
                try
                {
                    da.Fill(dt);
                }
                catch (Exception Ex)
                {
                    MessageBox.Show(Ex.Message.ToString());
                }

                if (dt.Rows.Count == 1)
                {
                    MessageBox.Show("Welcome");

                    Cashier cu = new Cashier();
                    this.Hide();
                    cu.Show();
                }
                else if (ID_TXT.Text == "")
                {
                    MessageBox.Show("ID not Empty");
                }
                else if (PASSWORD_TXT.Text == "")
                {
                    MessageBox.Show("Password not Empty");
                }
                else
                {
                    MessageBox.Show("Check your userid and password");
                    ID_TXT.Text       = "";
                    PASSWORD_TXT.Text = "";
                }
            }
        }