var DDSPEED = 10;
var DDTIMER = 15;

// main function to handle the mouse events //
function ddMenu(id,d){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearInterval(c.timer);
  if(d == 1){
    clearTimeout(h.timer);
    if(c.maxh && c.maxh <= c.offsetHeight){return}
    else if(!c.maxh){
      c.style.display = 'block';
      c.style.height = 'auto';
      c.maxh = c.offsetHeight;
      c.style.height = '0px';
    }
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }else{
    h.timer = setTimeout(function(){ddCollapse(c)},50);
  }
}

// collapse the menu //
function ddCollapse(c){
  c.timer = setInterval(function(){ddSlide(c,-1)},DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){ddSlide(c,1)},DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d){
  var currh = c.offsetHeight;
  var dist;
  if(d == 1){
    dist = (Math.round((c.maxh - currh) / DDSPEED));
  }else{
    dist = (Math.round(currh / DDSPEED));
  }
  if(dist <= 1 && d == 1){
    dist = 1;
  }
  c.style.height = currh + (dist * d) + 'px';
  c.style.opacity = currh / c.maxh;
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  if((currh < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}




var FadeDurationMS=1000;
function SetOpacity(object,opacityPct)
{
	object.style.filter = 'alpha(opacity=' + opacityPct + ')';
	object.style.MozOpacity = opacityPct/100;
	object.style.opacity = opacityPct/100;
}
function ChangeOpacity(id,msDuration,msStart,fromO,toO)
{
	var element=document.getElementById(id);
	var msNow = (new Date()).getTime();
	var opacity = fromO + (toO - fromO) * (msNow - msStart) / msDuration;
	if (opacity>=100)
	{
		SetOpacity(element,100);
		element.timer = undefined;
	}
	else if (opacity<=0)
	{
		SetOpacity(element,0);
		element.timer = undefined;
	}
	else 
	{
		SetOpacity(element,opacity);
		element.timer = window.setTimeout("ChangeOpacity('" + id + "'," + msDuration + "," + msStart + "," + fromO + "," + toO + ")",10);
	}
}
function FadeInImage(foregroundID,newImage,backgroundID)
{
	var foreground=document.getElementById(foregroundID);
	if (foreground.timer) window.clearTimeout(foreground.timer);

	if (backgroundID)
	{
		var background=document.getElementById(backgroundID);
		if (background)
		{
			if (background.src)
			{
				foreground.src = background.src;	
				SetOpacity(foreground,100);
			}
			background.src = newImage;
			background.style.backgroundImage = 'url(' + newImage + ')';
			background.style.backgroundRepeat = 'no-repeat';
			var startMS = (new Date()).getTime();
			foreground.timer = window.setTimeout("ChangeOpacity('" + foregroundID + "'," + FadeDurationMS + "," + startMS + ",10,0)",10);
		}
	} else {
		foreground.src = newImage;
	}
}
var slideCache = new Array();
function RunSlideShow(pictureID,backgroundID,imageFiles,displaySecs)
{
	var imageSeparator = imageFiles.indexOf(";");
	var nextImage = imageFiles.substring(0,imageSeparator);
	FadeInImage(pictureID,nextImage,backgroundID);
	var futureImages= imageFiles.substring(imageSeparator+1,imageFiles.length)
		+ ';' + nextImage;
	setTimeout("RunSlideShow('"+pictureID+"','"+backgroundID+"','"+futureImages+"',"+displaySecs+")",
		displaySecs*1000);
	// Cache the next image to improve performance.
	imageSeparator = futureImages.indexOf(";");
	nextImage = futureImages.substring(0,imageSeparator);
	if (slideCache[nextImage] == null)
	{
		slideCache[nextImage] = new Image;
		slideCache[nextImage].src = nextImage;
	}
}