⤷ Create random number

Use Randomize procedure for initialization random number generator and Random function for creating random number.
Parameter of Random function shows interval for random numbers.
If this parameter is 100 then random numbers will be between 0 and 99.

procedure TForm1.Button1Click(Sender: TObject);
begin
  Randomize;
  Label1.Caption:=IntToStr(Random(100));
end;
More for developers