$(document).ready(function(){
  var panel13_currentPosition = 0;
  var panel13_slideWidth = 600;
  var panel13_slides = $('.panel13_slide');
  var panel13_numberOfSlides = panel13_slides.length;

  // Remove scrollbar in JS
  $('#panel13_slideshow').css('overflow', 'hidden');
  $('#panel13_slideshow').css('width', '580px');
  $('.ninesixty .panel .details').css('width', '330px');
  $('.ninesixty .panel #panel13_slideshow').css('width', '580px');

  // Wrap all .slides with #slideInner div
  panel13_slides
  .wrapAll('<div id="panel13_slideInner"></div>')
  // Float left to display horizontally, readjust .slides width
  .css({
    'float' : 'left',
    'width' : panel13_slideWidth
  });

  // Set #slideInner width equal to total width of all slides
  $('#panel13_slideInner').css('width', panel13_slideWidth * panel13_numberOfSlides);

  // Insert left and right arrow controls in the DOM
  $('.ninesixty #panel13 .link')
  	.append('<div id="panel13_slideshow_controls"><span class="panel13_control" id="panel13_previous">Previous</span><span class="panel13_control" id="panel13_next">Next</span></div>');

  // Hide left arrow control on first load
  manageControls(panel13_currentPosition);

  // Create event listeners for .controls clicks
  $('.panel13_control')
    .bind('click', function(){
    // Determine new position
      panel13_currentPosition = ($(this).attr('id')=='panel13_next')
    ? panel13_currentPosition+1 : panel13_currentPosition-1;

      // Hide / show controls
      manageControls(panel13_currentPosition);
      // Move slideInner using margin-left
      $('#panel13_slideInner').animate({
        'marginLeft' : panel13_slideWidth*(-panel13_currentPosition)
      });
    });

  // manageControls: Hides and shows controls depending on currentPosition
  function manageControls(position){
    // Hide left arrow if position is first slide
    if(position==0){ $('#panel13_previous').hide() }
    else{ $('#panel13_previous').show() }
    // Hide right arrow if position is last slide
    if(position==panel13_numberOfSlides-1){ $('#panel13_next').hide() }
    else{ $('#panel13_next').show() }
    }
  });