LIST HOOKS

     To use a procedure as a list hook it must:

     1) Be a procedure declared with two passed parameters - a variable
     character and a byte  (indicating the highlighted topic). For example,

          PROCEDURE BOBS_HOOK(VAR C:CHAR;HITOPIC:BYTE);
          BEGIN
              .............
          END;

     2) Be declared as a far procedure, i.e. precede the procedure with a
     {$F+} compiler directive and succeed the procedure with the {$F-}
     compiler directive.

     The technique of assigning or hooking the procedure for Turbo Pascal
     5.0 is different from version 4.0:

     Turbo 5 Users - the LTTT variable includes a field HOOK which should
     be set to the procedure name, e.g.

          LTTT.HOOK := BOBS_HOOK;

     Turbo 4 Users - a global variable L_UserHook (of type Pointer) should
     point to the procedure with the @ directive, e.g.

          L_USERHOOK := @BOBS_HOOK


     The Hooked procedure will be passed the character the user just
     pressed and the number of the highlighted topic. The Hooked procedure
     can update the character pressed, and if the character is changed to a
     null (i.e. #0) then the pressed character is ignored, i.e. the system
     waits for the user to press another character. Change the character to
     an End_Chars to terminate the input.