private void DateLoan_Click(object sender, RoutedEventArgs e)//
{
if (lStartBox.SelectedDate != null && lEndBox.SelectedDate != null && lStartBox.SelectedDate < lEndBox.SelectedDate)
{
var now = DateTime.Now;
loanList.ItemsSource = null;
loanList.ItemsSource = lo.DateLoan(lStartBox.SelectedDate ?? now, lEndBox.SelectedDate ?? now, choiceLoan.SelectedItem as string);
}
else
{
MessageBox.Show("Please select a correct arbitrary period");
}
}