private void btn_submit_Click(object sender, EventArgs e)
        {
            EncryptPassword encrypt = new EncryptPassword();

            SessionManagement.Username = txt_username.Text.Trim();
            SessionManagement.Password = txt_password.Text.Trim();

            LoginDAL loginDAL = new LoginDAL();

            if (loginDAL.AuthenticateUser())
            {
                MessageBox.Show("Successfully logged in", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
                frmMainMenu mainMenu = new frmMainMenu();
                mainMenu.Show();
                Hide();
            }
            else
            {
                MessageBox.Show("Fail to login. Please try again", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
            txt_username.Clear();
            txt_password.Clear();
        }