private void btnok_Click(object sender, EventArgs e)
        {
            //validation
            if (txtusername.SelectedItem == "")
            {
                MessageBox.Show("Select username");
                txtusername.Focus();
            }
            else if (btnreset.Text == "")
            {
                MessageBox.Show("password is Required!");
                btnreset.Focus();
            }
            else
            {
                bool r = validate_login(txtusername.Text, btnreset.Text);
                if (r == true)
                {
                    PharmSoft cs = new PharmSoft();
                    this.Hide();

                    cs.userid.Text       = userid;
                    cs.lblUsername.Text  = username;
                    cs.lblRole.Text      = role;
                    cs.lblFull_Name.Text = fullname;
                    cs.Show();
                }

                else
                {
                    MessageBox.Show("incorrect login credentials");
                    txtusername.Text = "";
                    btnreset.Text    = "";
                    txtusername.Focus();
                }
            }
        }