var scrollPos = 0;
var scrollWidth = 0;
var loop = false;
var timer;

function updateArrows() {
	scrollWidth = document.getElementById("lastImg").offsetWidth + document.getElementById("lastImg").offsetLeft 
		- document.getElementById("thumbs").offsetWidth;
	if (scrollPos <= -scrollWidth) {
		document.getElementById("rightarrow").style.display="none";
	} else {
		document.getElementById("rightarrow").style.display="";
	}
	if (scrollPos >= 0) {
		document.getElementById("leftarrow").style.display="none";
	} else {
		document.getElementById("leftarrow").style.display="";
	}
}

function scrollRight() {
	scrollright(false);
}

function scrollRight(slow) {
	var inc = 2;
	var timeout = 10;
	if (slow) {
		inc = 0.4;
		timeout = 10;
	}
	if (scrollPos <= -scrollWidth) {
		updateArrows();
		loop = false;
		clearTimeout(timer);
		return;
	}
	scrollPos = scrollPos - inc;
	document.getElementById("thumbs").style.left=scrollPos+"px";
	if (loop) {
		timer = setTimeout("scrollRight("+slow+")", timeout);
	}
}

function scrollLeft() {
	if (scrollPos >= 0) {
		updateArrows();
		loop = false;
		clearTimeout(timer);
		return;
	}
	scrollPos = scrollPos + 2;
	document.getElementById("thumbs").style.left=scrollPos+"px";
	if (loop) {
		timer = setTimeout("scrollLeft()", 10);
	}
}

function scroll(val) {
	if (val == 1) {
		loop = false;
		clearTimeout(timer);
		loop = true;
		scrollWidth = document.getElementById("lastImg").offsetWidth + document.getElementById("lastImg").offsetLeft 
			- document.getElementById("thumbs").offsetWidth;
		scrollRight();
	} else
	if (val == -1) {
		loop = false;
		clearTimeout(timer);
		loop = true;
		scrollLeft();
	} else {
		loop = false;
		clearTimeout(timer);
	}
	updateArrows();
}

function startScroll() {
 	if (document.getElementById("rightarrow").style.display == "") {
		loop = true;
		scrollWidth = document.getElementById("lastImg").offsetWidth + document.getElementById("lastImg").offsetLeft 
			- document.getElementById("thumbs").offsetWidth;
		scrollRight(true);
		updateArrows();
	}
}