for i := 1 to length(plain.Text) do
      begin
        x := ord(plain.text[i]);
        if table[x] = '0' then
          table[x] := inttostr((ord(dat.text[i])));
        if i mod 2000 = 0 then
        begin
          Progressbar1.Position := Progressbar1.Position + 1;
          Application.ProcessMessages;
        end;
      end;