var inScroll     = false;
var scrollAmount = 0;

// run setup on dom load
document.observe("dom:loaded", function() {

  // add handlers for gallery scroller
  if( $('scroll_left') && $('scroll_right') ) {
    $('scroll_left').observe('mouseover', startScrollLeft);
    $('scroll_right').observe('mouseover', startScrollRight);
    $('scroll_left').observe('mouseout', stopScroll);
    $('scroll_right').observe('mouseout', stopScroll);
  }
});

function stopScroll(event){
  inScroll = false;
}

function startScrollLeft(event){
  scrollAmount = -5;
  inScroll     = true;

  doScroll();
}

function startScrollRight(event){
  scrollAmount = 5;
  inScroll     = true;

  doScroll();
}

function doScroll(){
  if( inScroll ){
    if( scrollAmount > 0 ){
      galleryEl = $('gallery');

      if( galleryEl ){
	if( galleryEl.clientWidth + galleryEl.scrollLeft < galleryEl.scrollWidth ){
          galleryEl.scrollLeft += scrollAmount;
        }
        else {
          inScroll = false;
        }
      }
    }
    else {
      galleryEl = $('gallery');

      if( galleryEl ){
	if( galleryEl.scrollLeft > 0 ){
          galleryEl.scrollLeft += scrollAmount;
        }
        else {
          inScroll = false;
        }
      }
    }

    setTimeout('doScroll();', 25);
  }
}