code: public boolean setSelectQuery(Rec selectTable, boolean bUpdateOnSelect)
      {       // If this screen can't accept a select BaseTable, find the one that can
          for (Enumeration<ScreenField> e = m_SFieldList.elements() ; e.hasMoreElements() ;)
          {   // This should only be called for Imaged GridScreens (Child windows would be deleted by now if Component)
              ScreenField sField = e.nextElement();
              if (sField.setSelectQuery(selectTable, bUpdateOnSelect))
                  return true;
          }
          return false;
      }
docs: Find the sub-screen that uses this grid query and set for selection.
  When you select a new record here, you read the same record in the SelectQuery.
  (Override to do something).
  @param selectTable The record which is synced on record change.
  @param bUpdateOnSelect Do I update the current record if a selection occurs.
  @return True if successful.