code: public BasePanel makeSubScreen()
      {
          if (this.isContactDisplay())
              return null;
          Record recHeader = this.getHeaderRecord();
          Record recMessageLog = this.getMainRecord();
          if (recHeader instanceof Company)   // Profile
              ((ReferenceField)recMessageLog.getField(MessageLog.CONTACT_ID)).setReferenceRecord(recHeader);   // Make sure this is hooked up
          return new MessageLogHeaderScreen(null, this, null, ScreenConstants.DONT_DISPLAY_FIELD_DESC, null);
      }
docs: Make a sub-screen.
  @return the new sub-screen.