GetCtlAction
GetCtlAction Query the address of the a control's action routine returns address of the tracking-action procedure (or NIL)
GetCtlAction returns the 4-byte value in the contrlAction field of a control's ControlRecord. This field is normally NIL, indicating to use the standard tracking action.
theControl is a handle leading to a variable-length ControlRecord structure. It specifies which control to query.
Returns: a 4-byte ProcPtr; either the address of a routine which is called internally by the control handler.
Notes: The routine whose address is obtained by GetCtlAction is called only when the final parameter of a call to TrackControl is -1. This call is functionally equivalent to:
ProcPtr whatProc;
whatProc = (* theControl )->contrlAction;