Динамические структуры, помогите дополнить Опции

[Brad Bellick]

Здравствуйте! Помогите пожалуйста доделать следующую процедуру(CreateList):

 type
PBook= ^TBook;
TBook=record
Next:PBook;
Author:string[15];
Name:string[41];
Publish:string[7];
year:word;
pages:word;
       end;
var
Book,
Beglist:Pbook;
Rel:pointer;
a:TBook;
Fbooks:file of TBook;
FI, FO:text;

procedure createlist;
begin
...
end;


procedure writelist(headline:string);
begin
rewrite(FO);
Writeln(FO);
Writeln(FO, Headline);
book:=beglist;
   while book<> NIL do
   begin
   with book^ do
   writeln(FO, Author:15, Name:41, Publish:7, Year:5, Pages:4);
   book:=book^.next;
   end;
   close(FO);
   end;
   procedure SortAuthor;
   var stop, first:boolean;
   book1, book2:Pbook;
   begin
       repeat
       stop:=true;
       book:=beglist;
       first:=true;
              while book^.next <> NIL do
              begin
                  if book^.Author > Book^.next^.Author then begin
                  book1:=book;
                  book:=book^.next;
                  if first then
                  beglist:=book
                    else
                    begin
                    book2:=beglist;
                    while book2^.next <> book1 do
                    book2:=book2^.next;
                    book2^.next:=book
                    end;
                    book1^.next :=book^.next;
                        book^.next:=book1;
                        stop:=false;
                        end;
                        first:=false;
                           book:=book^.next;
                           end;
            until stop;
            end;
  procedure writefile;
  begin
  assign (Fbooks, 'z6file.txt');
  rewrite(Fbooks);
  book:=beglist;
     while book <> NIL do
     begin
         write(Fbooks, Book^);
         book:=book^.next;
         end;
     close(Fbooks);
     end;
     procedure readfile;
     var
     k:integer;
     book1:Pbook;
     begin
     reset(FBooks);
     k:=filesize(FBooks);
     release(Rel);
     beglist:=NIL;
     while k>= 0 do
     begin
         book1:=book;
         dec(k);
             if k<0 then
             break;
             seek(FBooks, k);
             New(book);
                if beglist = NIL then
                Beglist:=book
                else
                book1^.next:=book;
            read(FBooks, Book^);
            Book^.next:=NIL
       end;
    close(Fbooks);
    end;
    begin
    Mark(Rel);
    Createlist;
    assign(FO, 'z6.res');
    writelist('Spisok:');
    SortAuthor;
    Writelist('otsortirovannij spisok:');
    Writefile;
    readfile;
    writelist('otsortirovano v protivopoloznom porjadke:');
    release(Rel);
END.