var backgrounds = new Array();
backgrounds[0] = "Aboutusbg.jpg";
//backgrounds[1] = "Belmont_Exterior_FrontB.jpg";
//backgrounds[2] = "Belmont_Exterior_Full.jpg";

var background_count = backgrounds.length;
// initializes the background image, stores the current index 
var bgIndex = 0;
var timerDelay = 5000;
var tmpTween = null;
var bgTween = null;
var timeBackgrounds = true;
var timeOut = 0;
var selectedCssClass = 'navItemSelected';
var unselectedCssClass = 'navItemUnselected';
var currentLink = '';
var currentSetIndex = 0;
var thumbSetLimit = 8; // Determines how many image links can appear at one time.

function displayBackground(i, _timed)
{
	if(backgrounds.length == 0)return;
	
	var tempBg = null;
	
	clearTimeout(timeOut);
	
	timeBackgrounds = _timed;
	
	if(currentLink == 'bg_'+i)
	{
		return;
	}
	else
	{
		if($(currentLink))
		{
			$(currentLink).className = 	unselectedCssClass;
		}
		currentLink = 'bg_'+i;
		bgIndex = i;
		
		if(timeBackgrounds)
		{
		//	if(bgIndex > (currentSetIndex + thumbSetLimit)-1)nextSet();
		//	else if(bgIndex < (currentSetIndex - thumbSetLimit)-1)prevSet();
		}
		
		if($(currentLink))
			$(currentLink).className = 	selectedCssClass;
	}
		
	if(currentBg == bgImageOne)	currentBg = bgImageTwo;
	else if(currentBg == bgImageTwo) currentBg = bgImageOne;
	else currentBg = bgImageOne;
	
	currentBg.src = null;
	currentBg.src = "images/"+backgrounds[i];
	currentBg.onload = onTmpBgLoaded;
	
	$(currentBg.id).setStyle('opacity', '0');
}
function onTmpBgLoaded()
{	
	var tempBg = null;
	$('site_bg_container').style.background = "";//('background', '');
	
	if(currentBg == bgImageOne)	tempBg = bgImageTwo;
	else tempBg = bgImageOne;
	
	tmpTween = $(currentBg.id).get('tween', {property: 'opacity', duration: 3000});
	tmpTween.complete = onImageSwapped;
	tmpTween.start(1);
	
	bgTween = $(tempBg.id).get('tween', {property: 'opacity', duration: 3000});
	bgTween.start(0);
}
function onImageSwapped()
{
	tmpTween.cancel();
	try{
	if(backgrounds.length > 1)onBackgroundTimer();
	}catch(e){alert(e)}
}
function onBackgroundTimer(){
	try{
	if(bgIndex < backgrounds.length-1) {bgIndex++;} else {bgIndex = 0;}
	if(timeBackgrounds)timeOut = setTimeout("displayBackground("+bgIndex+", true)", timerDelay);
	}catch(e){alert(e)}
}
function initBgThumbSet()
{
	if(backgrounds.length > thumbSetLimit)
	{
		hideBgThumbs();
		showBgThumbSet(currentSetIndex, thumbSetLimit);
	}
	else
	{
		$('nextSet').setStyle('display', 'none');
		$('prevSet').setStyle('display', 'none');
	}
}
function nextSet()
{
	hideBgThumbs();
	currentSetIndex+=thumbSetLimit;
	if(!showBgThumbSet(currentSetIndex, thumbSetLimit))
	{
		prevSet();
	}
	
}
function prevSet()
{
	if((currentSetIndex - thumbSetLimit) < 0)return;
	
	hideBgThumbs();
	currentSetIndex-=thumbSetLimit;
	showBgThumbSet(currentSetIndex, thumbSetLimit);
}
function showBgThumbSet(offset, limit)
{	
	var len = (offset + limit);
	var remainder = backgrounds.length - offset;
//	alert("Offset: " + offset +" Length: "+ len + " Remainder: " + remainder);
	
	if(offset >= backgrounds.length - 1)return false;
	if(offset < 0)return false;
	
	if(len >= backgrounds.length)
	{
		if(remainder <= 0)return false;
		else len = offset + remainder;
	}
	for(var i = offset; i < len; i++)
	{
		$('container_'+i).setStyle('display', 'block');
	//	$('bg_'+i).setStyle('display', 'block');
	}
	
	return true;
}
function hideBgThumbSet(offset, limit, toEnd) 
{
	for(var i = 0; i < backgrounds.length; i++)
	{
		$('container_'+i).setStyle('display', 'none');
	}
}
function hideBgThumbs() 
{
	for(var i = 0; i < backgrounds.length; i++)
	{
		$('container_'+i).setStyle('display', 'none');
	}
}
document.addEvent('domready', initBgThumbSet);