if (tbxSifra.Text != string.Empty)
            {
                MessageBox.Show("Da bi ste uneli novog morate da obrisete sifru");
            }
            Klijent x = new Klijent();
            if (tbxIme.Text!=string.Empty) x.Ime = tbxIme.Text;
            if (tbxPrezime.Text != string.Empty) x.Prezime = tbxPrezime.Text;
            if (tbxAdresa.Text != string.Empty) x.Adresa = tbxAdresa.Text;
            if (tbxTelefon.Text != string.Empty) x.Telefon = tbxTelefon.Text;
            if (tbxMail.Text != string.Empty) x.Email = tbxMail.Text;
            if (rbtnDa.Checked) x.Aktivan = true;
            else x.Aktivan = false;
            //citanje iz combobox-a
            if (cbxGrad.SelectedIndex > -1)
            {
                x.GradId = (int)cbxGrad.SelectedValue;
            }
            try
            {
                if (x.Upisi())
                {
                    tbxSifra.Text = x.KlijentID.ToString();
                    MessageBox.Show("Klijent upisan");
                }
                else throw new Exception(x.ErrorMessage);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }