private void btnRendezVousΟκ_Click(object sender, RoutedEventArgs e)
        {
            string rccodeid = ((R_Modi)Rdatagrid.SelectedItem).RCode.ToString();
            R_Modi result   = entities.R_Modi.SingleOrDefault(b => b.RCode == rccodeid);

            if (result != null)
            {
                result.RSuccess = "OK";
                entities.SaveChanges();
                LoadDatagrid();
            }
        }
        private void btnEdit_Click(object sender, RoutedEventArgs e)
        {
            //na ftiaxw to koumpi ananewsh stoixeiwn
            string rccodeid = ((R_Modi)Rdatagrid.SelectedItem).RCode.ToString();
            R_Modi result   = entities.R_Modi.SingleOrDefault(b => b.RCode == rccodeid);

            if (result != null)
            {
                result.RCustomerName    = rnametxt.Text.ToString();
                result.RCustomerSurname = rsurnametxt.Text.ToString();
                result.RDate            = rDate.Text.ToString();
                result.RWeddingDate     = rWedDate.Text.ToString();
                result.RDateHour        = rhourtxt.Text.ToString();
                result.RCustomerPhone   = rphonetxt.Text.ToString();
                result.RCustomerCity    = rcitytxt.Text.ToString();
                entities.SaveChanges();
                LoadDatagrid();
                Clear();
            }
        }