Два окна

  if listbox1.Items.Count<>0 then
  if (not Assigned(Form2)) then begin
  Form2:=TForm2.Create(Self);
  Form2.ShowModal;
  end;

procedure TForm2.Button1Click(Sender: TObject);
var s:string;
  i:integer;
begin
   printer.Canvas.Font.Size:=100;
   printersetupdialog1.execute;
   printer.BeginDoc;
   printer.Canvas.TextOut(200,0,edit1.Text);
   for i:=1 to form1.listbox1.items.count do begin
   s:=inttostr(i)+'). ';
   case RadioGroup1.ItemIndex of
   0: s+=form1.listbox1.items[i-1];
   2: s+=form1.listbox2.items[i-1];
   1: s+=form1.ListBox1.Items[i-1]+'  -  '+form1.listbox2.items[i-1];
   end;
   printer.Canvas.TextOut(200,i*200,s);
   end;
   printer.endDoc;
   form2.close;
end;

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;
  Form2 := nil;
end;

procedure TForm2.FormClose(Sender: TObject; var CloseAction: TCloseAction);
begin
  CloseAction:=caFree;
end;

  if listbox1.Items.Count<>0 then
    TForm2.Create(nil).ShowModal;