[san-46]

Код:

procedure TForm1.Button1Click(Sender: TObject);
var
  i:integer;
begin
  randomize;
  for i:=1 to 10 do
  begin
    label1.caption:=inttostr(randomrange(1,100));
    Application.ProcessMessages;
    Windows.SleepEx(200,false);
  end;
end;

Из справки: "To initialize the random number generator, add a single call Randomize..."