var ContentHeight = 200;  	//Height of divs when they open
var TimeToSlide = 1000.0;	//Speed for slide to open or close
var openAccordion = '';		//Nothing open when page brought up

function runAccordion(index, AccHeight)
{
  var nID = "Accordion" + index + "Content";

//  if(AccHeight == 0)			If current menu doesn't have submenus
//    nID = '';				Close current open menu

//  if(openAccordion == nID)		If openAccordion is current open menu
//    nID = '';				Close current open menu
   
  if(AccHeight != 0)			//If current menu has submenus
    ContentHeight = AccHeight;	//Height of divs when they open

  if(openAccordion == "")    		//If menu not open
    setTimeout("animate(" + new Date().getTime() + "," + TimeToSlide + ",'"
      + openAccordion + "','" + nID + "')", 33);
      //Call the animate function using the parameters listed  

  openAccordion = nID;         	//Set openAccordion to the value in nID
}

function animate(lastTick, timeLeft, closingId, openingId)
{  
  var curTick = new Date().getTime();
  var elapsedTicks = curTick - lastTick;
 
  var opening = (openingId == '') ? null : document.getElementById(openingId);
  var closing = (closingId == '') ? null : document.getElementById(closingId);
 
  if(timeLeft <= elapsedTicks)
  {
    if(opening != null)
      opening.style.height = ContentHeight + 'px';
   
    if(closing != null)
    {
      closing.style.display = 'none';
      closing.style.height = '0px';
    }
    return;
  }
 
  timeLeft -= elapsedTicks;
  var newClosedHeight = Math.round((timeLeft/TimeToSlide) * ContentHeight);

  if(opening != null)
  {
    if(opening.style.display != 'block')
      opening.style.display = 'block';
    opening.style.height = (ContentHeight - newClosedHeight) + 'px';
  }
 
  if(closing != null)
    closing.style.height = newClosedHeight + 'px';

  setTimeout("animate(" + curTick + "," + timeLeft + ",'"
      + closingId + "','" + openingId + "')", 33);
}

/* So the animate function takes 4 arguments - the last time the animation was updated, the amount of time left before the animation should complete, the element id of the closing menu, and the element id of the opening menu. The reason we care about time here is that the code always makes sure the animation completes in the amount of time specified in TimeToSlide. If we didn't do that, on slow computers the slide would have the potential to take much longer than TimeToSlide.

Because of all that, the first thing we do in the animation function is figure out how much time has passed since the last animation iteration. If that amount of time is greater than (or equal to) the amount of time left in the animation (as specified in timeLeft), we finish the animation. We do this by setting the opening menu (if there is an opening menu) to its full size, setting the size of the closing menu (if there is one) to 0 and making it invisible, and then returning out, thereby ending the animation.

If there is still time left in the animation, we calculate the ratio of time left to the total time in the animation, and multiply it by the the full menu height. This returns the new value for the height of the closing menu. Now, if there is a menu we are opening, we first make sure it is visible (because closed menus are initially invisible), and if it isn't we make it visible. Next we set the new height, which is full menu height minus the new height of the closing menu (this way as one menu closes, the other opens exactly in sync). Then, if there is a menu we are closing, we set its new height.

Finally, we do a new setTimeout call to animate, with the new values for the last time the animation was updated and the amount of time left in the animation. */