var eBook_scroll_timer = false;

function scrollEBookLeft() {
  scrollEBook('outerEBookLayer', 'innerEBookLayer', 'left', 8, 1);
}

function scrollEBookRight() {
  scrollEBook('outerEBookLayer', 'innerEBookLayer', 'right', 8, 1);
}

function scrollEBookStop() {
  if (eBook_scroll_timer !== false) {
    clearTimeout(eBook_scroll_timer);
    eBook_scroll_timer = false;
  }
}

function scrollEBook(outer_layer_id, layer_id, direction, speed, start_speed) {
  var layer_object = document.getElementById(layer_id);

  var layer_leftEdge = parseInt(layer_object.style.left);
  var scroll_width = (document.getElementById(outer_layer_id).offsetWidth - layer_object.offsetWidth);

  if (start_speed === undefined) {
    var spart_speed = 1;
  }

	//alert('outer width: ' + document.getElementById(outer_layer_id).offsetWidth);
	//alert('inner width: ' + layer_object.offsetWidth);
	//alert('inner left pos: ' + layer_leftEdge);
	//alert('scroll width: ' + scroll_width);

  if ((direction == 'right') && (layer_leftEdge > scroll_width)) {
    if (layer_leftEdge - start_speed > scroll_width) {
      layer_object.style.left = String(layer_leftEdge - start_speed) + 'px';
    }
    else {
      layer_object.style.left = String(scroll_width) + 'px';
    }
  }
  else if ((direction == 'left') && (layer_leftEdge < 0)) {
    if (layer_leftEdge <= -start_speed) {
      layer_object.style.left = String(layer_leftEdge + start_speed) + 'px';
    }
    else {
      layer_object.style.left = '0px';
    }
  }

  if (start_speed < speed) {
    start_speed++;
  }

  eBook_scroll_timer = setTimeout('scrollEBook("' + outer_layer_id + '", "' + layer_id + '", "' + direction + '", ' + speed + ', ' + start_speed + ')', 50);
}