var scroll_i = 0
var scroll_speed = 2
function scroll() {
  scroll_i = scroll_i + scroll_speed
  var scroll_div = document.getElementById("scroller")
  scroll_div.scrollTop = scroll_i
  if (scroll_i > scroll_div.scrollHeight - 160) {
   scroll_i = 0
  }
  var scroll_t=setTimeout("scroll()", 100)
}