$(document).ready(function(){
  var news_currentPosition = 0;
  var news_slideWidth = 960;
  var news_slides = $('.news_slide');
  var news_numberOfSlides = news_slides.length;

  // Remove scrollbar in JS
  $('#news_slideshow').css('overflow', 'hidden');
  $('#news_slideshow').css('width', '960px');
  $('#news').css('width', '960px');

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

  // Set #slideInner width equal to total width of all slides
  $('#news_slideInner').css('width', news_slideWidth * news_numberOfSlides);

  // Insert left and right arrow controls in the DOM
  $('#news')
  	.append('<div id="news_slideshow_controls"><span class="news_control" id="newer">Newer</span><span class="news_control" id="older">Older</span></div>');

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

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

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

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