private void btnAdd_Click(object sender, RoutedEventArgs e)
        {
            RadComboBoxItem selectedItem = comboSex.SelectedItem as RadComboBoxItem;
            Kontakt         kontakt      = new Kontakt();
            Lokacija        lokacija     = new Lokacija();



            string pom1 = REST.EmailCheck(txtEmail.Text.ToString());

            if (pom1.ToString() == "[]")
            {
                if (txtAddress.Text != null && txtAddress.Text != "" && txtPlace.Text != null && txtPlace.Text != "" && txtEmail.Text != null && txtEmail.Text != "" && txtPhone.Text != null && txtPhone.Text != "" && txtName.Text != null && txtName.Text != "" && txtLastname.Text != null && txtLastname.Text != "" &&
                    txtID.Text != null && txtID.Text != "" && passPassword.Password != null && passPassword.Password != "" && dateDateOfBirth.SelectedDate != null && selectedItem.Content.ToString() != null && selectedItem.Content.ToString() != "")
                {
                    if (selectedItem.Content.ToString() == "Ž")
                    {
                        pol = 'z';
                    }
                    else
                    {
                        pol = 'm';
                    }
                    selectedItem = comboBloodType.SelectedItem as RadComboBoxItem;
                    Donor donor = new Donor();
                    donor.Ime             = txtName.Text;
                    donor.Prezime         = txtLastname.Text;
                    donor.Pol             = pol.ToString();
                    donor.RegistarskiBroj = txtID.Text;
                    donor.Lozinka         = passPassword.Password;
                    donor.DatumRodjenja   = dateDateOfBirth.SelectedDate;
                    donor.KrvnaGrupaDonor = selectedItem.Content.ToString();
                    lokacija.Mjesto       = txtPlace.Text;
                    lokacija.Adresa       = txtAddress.Text;
                    kontakt.BrojTelefona  = txtPhone.Text;
                    kontakt.Email         = txtEmail.Text;


                    //upis u tabelu donor
                    var response = REST.Post("donor", donor);

                    //donor ID
                    string pom = response.Headers.Location.ToString();

                    Regex regex = new Regex(@"api/Donor/(\w+)");
                    Match match = regex.Match(pom);
                    pom = match.Groups[1].Value;
                    int ID = Convert.ToInt32(pom);
                    //
                    kontakt.DonorId = ID;
                    //upis u tabelu lokacija
                    response = REST.Post("lokacija", lokacija);
                    //lokacija ID
                    pom = response.Headers.Location.ToString();

                    regex = new Regex(@"api/Lokacija/(\w+)");
                    match = regex.Match(pom);
                    pom   = match.Groups[1].Value;
                    ID    = Convert.ToInt32(pom);
                    //
                    kontakt.LokacijaId = ID;

                    //upis u tabelu kontakt
                    REST.Post("kontakt", kontakt);

                    NavigationService.Navigate(new DonorsPage());
                }
            }
            else
            {
                txtEmail.Foreground = Brushes.Red;
            }
        }