var scrollAreaWidth = 900;
var scrollMinY = 0;
var scrollTime = 1000;
var scrollPages = 1;
var scrollCurrPage = 1;
var circleFullImg = "";
var circleEmptyImg = "";
var scrollInterval = 20;
var scrollIntervalID = -1;
var scrollSpeed = 5;
var scrollCurrSpeed = 0;
var scrollPosition = 0;

function initSidescroller (areaWidth, totalWidth, pages)
{
	scrollAreaWidth = areaWidth;
	scrollMinY = -(totalWidth - areaWidth) + 13;
	scrollPages = pages;
	if (totalWidth > areaWidth)
	{
		$('#sidescrollerLeft').hover (startScrollRightCallback, stopScrollCallback);
		$('#sidescrollerRight').hover (startScrollLeftCallback, stopScrollCallback);
	}
	else
	{
		$('#sidescrollerLeft').hide ();
		$('#sidescrollerRight').hide ();
	}
}

function startScrollLeftCallback ()
{
	scrollCurrSpeed = -scrollSpeed;
	scrollIntervalID = setInterval ("moveSlider()", scrollInterval);
}

function startScrollRightCallback ()
{
	scrollCurrSpeed = scrollSpeed;
	scrollIntervalID = setInterval ("moveSlider()", scrollInterval);
}

function stopScrollCallback ()
{
	if (scrollIntervalID != -1)
	{
		clearInterval (scrollIntervalID);
		scrollIntervalID = -1;
	}
}

function moveSlider ()
{
	scrollPosition += scrollCurrSpeed;
	if (scrollPosition > 0)
	{
		scrollPosition = 0;
		stopScrollCallback ();
	}
	else if (scrollPosition < scrollMinY)
	{
		scrollPosition = scrollMinY;
		stopScrollCallback ();
	}
	//updateCircles ();
	$('#sidescrollerBoxes').css ('left', scrollPosition + 'px');
}

function updateCircles ()
{
	var page = Math.floor ( (scrollAreaWidth - scrollPosition - 10) / scrollAreaWidth) + 1;
	if (page != scrollCurrPage)
	{
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleEmptyImg);
		scrollCurrPage = page;
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleFullImg);
	}
}

function scrollLeftCallback () 
{
	if (scrollCurrPage < scrollPages)
	{
		$('#sidescrollerBoxes').animate ({left: '-=' + scrollAreaWidth}, scrollTime);
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleEmptyImg);
		scrollCurrPage++;
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleFullImg);
	}
}

function scrollRightCallback () 
{
	if (scrollCurrPage > 1)
	{
		$('#sidescrollerBoxes').animate ({left: '+=' + scrollAreaWidth}, scrollTime);
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleEmptyImg);
		scrollCurrPage--;
		$('#sidescrollerCircle' + scrollCurrPage).attr("src", circleFullImg);
	}
}