private void repositoryItemLookUpEdit1_ButtonClick(object sender, DevExpress.XtraEditors.Controls.ButtonPressedEventArgs e)
 {
     if (e.Button.Kind == DevExpress.XtraEditors.Controls.ButtonPredefines.Delete)
     {
         LookUpEdit editor = (LookUpEdit)sender;
         editor.CancelPopup();
         editor.EditValue = null;
     }
 }