Я тут написал генератор паролей.Думаю для примера сойдёт. Прога вроде простая, но если возникнут вопросы пишите, я добавлю коментарии. Сдесь EXE файл _files.adamant.ua/3362
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, Spin;

type
TForm1 = class(TForm)
Button1: TButton;
Label1: TLabel;
CheckBox1: TCheckBox;
CheckBox2: TCheckBox;
CheckBox3: TCheckBox;
CheckBox4: TCheckBox;
CheckBox5: TCheckBox;
CheckBox6: TCheckBox;
Button2: TButton;
SaveDialog1: TSaveDialog;
Button3: TButton;
SpinEdit1: TSpinEdit;
Label2: TLabel;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button3Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
buf:string;
implementation
const
cifri: array [1..10] of char =('1','2','3','4','5','6','7','8','9','0');
symbol: array [1..17] of char =('<','>','@','!','(',')','-','?','[',']','+','{','}',',','.','=','*');
RusL: array [1..33] of char =('й','ц','у','к','е','н','г','ш','щ','з ','х','ъ', 'ф','ы','в','а','п',
'р','о','л','д','ж','э','я','ч','с','м', 'и','т','ь ','б','ю','ё');
RusB: array [1..33] of char =('Й','Ц','У','К','Е','Н','Г','Ш','Щ','З ','Х','Ъ', 'Ф','Ы','В','А','П',
'Р','О','Л','Д','Ж','Э','Я','Ч','С','М', 'И','Т','Ь ','Б','Ю','Ё');
EngL: array [1..26] of char =('q','w','e','r','t','y','u','i','o','p','a','s', 'd','f','g','h','j',
'k','l','z','x','c','v','b','n','m');
EngB: array [1..26] of char =('Q','W','E','R','T','Y','U','I','O','P','A','S', 'D','F','G','H','J',
'K','L','Z','X','C','V','B','N','M');
{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
i,n,c:integer;
begin
buf:='';
randomize;
n:=SpinEdit1.Value;
i:=1;
repeat
c:=random(6);
If (c=0) and (CheckBox1.Checked) then
begin
buf:=buf+cifri[random(9)+1];
i:=i+1;
end else
If (c=1) and (CheckBox2.Checked) then
begin
buf:=buf+symbol[random(16)+1];
i:=i+1;
end;
If (c=2) and (CheckBox3.Checked) then
begin
buf:=buf+RusL[random(32)+1];
i:=i+1;
end;
If (c=3) and (CheckBox4.Checked) then
begin
buf:=buf+RusB[random(32)+1];
i:=i+1;
end;
If (c=4) and (CheckBox5.Checked) then
begin
buf:=buf+EngL[random(25)+1];
i:=i+1;
end;
If (c=5) and (CheckBox6.Checked) then
begin
buf:=buf+EngB[random(25)+1];
i:=i+1;
end;
until i=n+1;
Label1.Caption:=buf;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
f:TextFile;
fname:String;
begin
If SaveDialog1.Execute then
begin
fname:=SaveDialog1.Filename;
AssignFile(f,fname);
Rewrite(f);
Write(f,buf);
CloseFile(f);
end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
SaveDialog1.Filter:='Текст|*.txt';
SaveDialog1.FileName:='*.txt';
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
Form1.Close;
end;

end.