var slidewidth = 152;
var currentslide = 0;
var totalslides = 5;
var pausetime = 9600;
var elem = document.getElementById('slider');
var scrollanim = {time:0, begin:0, change:0.0, duration:0.0, element:null, timer:null};
var autoint;

function initScroller() {
	scrollanim.element = document.getElementById('slider');
}

function startScroll(direction) {

	var begin = 0;
	var change= 0;
	
	if (direction == 'right') {
		begin = (currentslide - 1) * slidewidth;
		change = slidewidth;	
	} else {
		begin = (currentslide + 1) * slidewidth;
		change = slidewidth * -1;		
	}
	
	scrollanim.time = 0;
	scrollanim.begin = begin;
	scrollanim.change = change;
	scrollanim.duration = 10;
	scrollanim.timer = setInterval("scrollHorizAnim();", 15);

}

function sineInOut(t, b, c, d) {
	return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
}

function scrollHorizAnim()
{
	if (scrollanim.time > scrollanim.duration) {
		clearInterval(scrollanim.timer);
		scrollanim.timer = null;
	}
	else {
		move = sineInOut(scrollanim.time, scrollanim.begin, scrollanim.change, scrollanim.duration);
		scrollanim.element.scrollLeft = move;
		scrollanim.time++;
	}
}

function goRight() {
	currentslide = currentslide + 1;
	if (currentslide > totalslides) {
		currentslide = 1;
		scrollanim.element.scrollLeft = 0;
	}
	startScroll('right');
}

function goLeft() {
	currentslide = currentslide - 1;
	if (currentslide < 0) {
		currentslide = totalslides - 1;
		scrollanim.element.scrollLeft = totalslides * slidewidth;
	}
	startScroll('left');
}

function pressLeft() {
	clearInterval(autoint);
	goLeft();
}

function pressRight() {
	clearInterval(autoint);
	goRight();
}

function startAuto() {
   autoint = setInterval('goRight()',pausetime);
}