Поменять строки местами

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Menus;
 
type
  TMass = record
    Name : string;
    Ratio : integer;
  end;
 
type
  TForm1 = class(TForm)
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    N2: TMenuItem;
    N3: TMenuItem;
    Memo1: TMemo;
    OpenDialog1: TOpenDialog;
    SaveDialog1: TSaveDialog;
    N4: TMenuItem;
    procedure N1Click(Sender: TObject);
    procedure N3Click(Sender: TObject);
    procedure N4Click(Sender: TObject);
    procedure N2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    f,ff : TextFile;
    FileName, s: ShortString;  
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.N1Click(Sender: TObject);
begin            //кнопка "Открыть"
  if OpenDialog1.Execute then begin
    Memo1.Lines.Clear;
    FileName := OpenDialog1.FileName; 
    AssignFile(f, FileName);  
    reset(f);           
    repeat
      readln(f, s);  
      Memo1.Lines.Add(s); 
    until eof(f);   
    CloseFile(f);  
  end;
end;
 
procedure TForm1.N3Click(Sender: TObject);
var              //кнопка "Записать"
  i : integer;
begin
  if SaveDialog1.Execute then
  begin
    FileName := SaveDialog1.FileName;
    AssignFile(f, FileName);
    rewrite(f);
    for i := 0 to Memo1.Lines.Count-1 do begin
      writeln(f, Memo1.Lines[i]);
    end;
    CloseFile(f);
  end;
end;
 
procedure TForm1.N4Click(Sender: TObject);
begin            //кнопка "Очистить"
  Memo1.Lines.Clear;
end;
 
procedure TForm1.N2Click(Sender: TObject);
type             //Кнопка "Обработать"
  TWord=string[20]; 
  TWords=array[1..100] of TWord;
var
 
  TextStr: string;  
  Words: TWords;  
  nw, i: integer;  
 
begin
  assignfile(f,FileName);  
  reset(f);
  assignfile(ff,'tfhfg');  
  rewrite(ff);
  nw:=0;
  while not eof(f) do
  begin
    readln(f,TextStr);  
    writeln(ff,TextStr); 
    while TextStr<>'' do
    begin
      Inc(nw);
      
 
    end;
  end;
  writeln(ff);
   for i:=1 to nw do writeln(ff,Words[i]);
  writeln(ff);
   for i:=nw downto 1 do writeln(ff,Words[i]);
  CloseFile(f);
  CloseFile(ff);
  end;
end.

for i := Memo1.Lines.Count-1 downto 0 begin
      writeln(f, Memo1.Lines[i]);

var f:file of string;

procedure TForm1.N2Click(Sender: TObject);
var
f,ff: File of Text;
BufStr: Array of String;
i: Integer;
begin
AssignFile(f,FileName);
Reset(f);
AssignFile(ff,'Test.txt');
ReWrite(ff);
i:=1;
While not (EOF(f)) do
begin
  SetLength(BufStr,i);
  Readln(f,BufStr[i-1]);
  Writeln(ff,BufStr[i-1]);
  Inc(i);
end;
CloseFile(f);
For i:=Length(BufStr)-1 downto 0 do Writeln(ff,BufStr[i]);
CloseFile(ff);
end;