The container control sends a WM_CONTROL (in Container Controls) message with the CN_ENTER notification code to its owner when either of the following occurs:

• The Enter key is pressed while the container window has the focus
  
• The select button is double-clicked while the pointer is over the container window.

param1
     USHORT              id                  /*  Container control ID. */
     USHORT              CN_ENTER            /*  Notification code. */

param2
     PNOTIFYRECORDENTER  pNotifyRecordEnter  /*  Pointer to the NOTIFYRECORDENTER structure. */