private void btnLogin_Click(object sender, EventArgs e) { //send txt username and pw to getuserlogin function var username = txtBox_Username.Text.Trim(); var password = txtBox_Password.Text.Trim(); DSLogin.KorisniksDataTable dtLogin = new DSLogin.KorisniksDataTable(); dtLogin.Clear(); DALogin.getKorisnikByUsernameAndPassword(dtLogin, username, password); if (dtLogin.Rows.Count == 1) { FrmDashboard formDashboard = new FrmDashboard(); this.Hide(); formDashboard.Show(); } else { MessageBox.Show("Check your username and password"); } }