procedure TForm1.Button1Click(Sender: TObject);
function PadString(nLength: Integer; Str, PadStr: string): string;
var
i: Integer;
tmpPad: string;
begin
result := Str;
if Length(Str) < nLength then begin
tmpPad := '';
for i := 0 to nLength - Length(Str) - 1 do
tmpPad := tmpPad + PadStr;
result := tmpPad + Str;
end;
end;
var
i: Integer;
begin
ListBox1.Clear;
for i:=1 to 99 do begin
ListBox1.Items.Add(PadString(3,IntToStr(i),'0'));
end;
end;