[NumLock]

Код:

function CreateBoundary(ALength: Integer): String;
begin
  Result:='--------';
  while Length(Result)<ALength do
  begin
    Result:=Result+Chr(Random(Ord('z')-Ord('a'))+Ord('a'));
    Result:=Result+Chr(Random(Ord('9')-Ord('0'))+Ord('0'));
    Result:=Result+Chr(Random(Ord('Z')-Ord('A'))+Ord('A'));
    Result:=Result+Chr(Random(Ord('9')-Ord('0'))+Ord('0'));
  end;
end;

Код:

Edit1.Text:=CreateBoundary(32);