private void btnLogin_Click(object sender, EventArgs e)
        {
            DALogin.GetLoginByKorisnickoImeAndLozinka(dsLogin.LoginPodaci, txtKorisnickoIme.Text, txtLozinka.Text);
            int count = dsLogin.LoginPodaci.Count;

            if (count == 1)
            {
                this.DialogResult = DialogResult.OK;
                this.Close();
            }
            else
            {
                lblError.Visible = true;
            }
        }