var timer_id;

function scroll_iframe(frm, h, v) {
  if (timer_id) clearTimeout(timer_id);

  if (window.frames[frm]) {
		window.frames[frm].scrollBy(h, v);

    timer_id = setTimeout("scroll_iframe('" + frm + "', '" + h + "', '" + v + "')", 20);
  }
}

function stopScroll() {
	if (timer_id) clearTimeout(timer_id);
}