private void TabItem_KeyUp(object sender, KeyEventArgs e)
 {
     EX.ViewModel.MainVM vm = this.DataContext as EX.ViewModel.MainVM;
     if (e.Key == Key.Escape)
     {
         vm.ResetEditDesctopVisitor();
     }
 }
 private void lb_KeyDown(object sender, KeyEventArgs e)
 {
     EX.ViewModel.MainVM vm = this.DataContext as EX.ViewModel.MainVM;
     if (e.Key == Key.Enter && btn_save_desctop.IsEnabled == false)
     {
         if ((vm != null) && (vm.AddVisitorToFact.CanExecute(null)))
         {
             stbo.Text = "";
             vm.AddVisitorToFact.Execute(null);
         }
     }
     else if (e.Key == Key.Enter && btn_save_desctop.IsEnabled == true)
     {
         vm.SaveEditVisitor.Execute(null);
         stbo.Focus();
     }
 }