/*
	if window.onload has not already been assigned a function,
	the function passed to addLoadEvent is simply assigned to window.onload.
	If window.onload has already been set, a brand new function is created which
	first calls the original onload handler, then calls the new handler afterwards. 
*/
function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}



function animateSlides()
{

	var homepageFeatures = document.getElementById("homepageFeatures");
	var currClass = homepageFeatures.className;
	var currSlideNum = currClass.substring(5,6);
	var nextSlideNum = "slide" + (((currSlideNum * 1) % 5) + 1);
	changeSlide(nextSlideNum);
}

function changeSlide(slideClass)
{
	var homepageFeatures = document.getElementById("homepageFeatures");
	homepageFeatures.className = "";
	homepageFeatures.className = slideClass;
}

function initSlideNav()
{
	var playingClassName = "playing";
	var slideTimer = new PeriodicalExecuter(animateSlides, 7);
	var slideNavAnchors = $$('ul#homepageFeaturesNav a');
	
	for(count = 0; count < slideNavAnchors.length; count++)
	{
		slideNavAnchors[count].onclick=function()
		{
			if(slideTimer)
			{
				slideTimer.stop();
			}
			changeSlide(this.className);
			
			var videoPlaying = $$('ul#homepageFeaturesSlides li.playing');
			if(videoPlaying.length)
			{
				for (countPlaying = 0; countPlaying < videoPlaying.length; countPlaying++)
				{
					videoPlaying[countPlaying].removeClassName(playingClassName);
				}
			}
		}
	}
	
	var featuredSlides = $$('ul#homepageFeaturesSlides li.video a');
	for(count = 0; count < featuredSlides.length; count++)
	{
		featuredSlides[count].onclick = function()
		{
			if(slideTimer)
			{
				slideTimer.stop();
			}
			this.parentNode.parentNode.parentNode.addClassName(playingClassName);
			return false;
		}
	}
}

addLoadEvent(initSlideNav);