private void Cancel_Click(object sender, RoutedEventArgs e)
        {
            OrderListView OLV = new OrderListView();

            OLV.DataContext = DataContext;
            OLV.Show();
            Close();
        }
        private void OrdersView_Click(object sender, RoutedEventArgs e)
        {
            OrderListView OLV = new OrderListView();

            OLV.SetViewModel();
            OLV.Show();
            Close();
        }
 private void Update_Click(object sender, RoutedEventArgs e)
 {
     if (ProductsCombo.SelectedItem != null && EmployersCombo.SelectedItem != null)
     {
         OrderListView OLV = new OrderListView();
         OLV.DataContext = DataContext;
         OLV.Show();
         Close();
     }
     else
     {
         MessageBox.Show("Введена не вся информация");
     }
 }