var scrollPos = 0;
var scrollTimer;

//preloads
if (document.images) {
  pic1 = new Image(20,20); 
  pic1.src = "/images/ui/right_scroll_disabled.png"; 

  pic2 = new Image(20,20); 
  pic2.src = "/images/ui/left_scroll.png"; 
}


function Scroll_Images_Right() {
	Scroll_Images(true, 80);
}
function Scroll_Images_Left() {
	Scroll_Images(false, 80);
}

function Start_Scroll_Images_Right() {
	Start_Scroll_Images(true);
}

function Start_Scroll_Images_Left() {
	Start_Scroll_Images(false);
}

function Start_Scroll_Images(direction) {
	Scroll_Images(direction, 10);
	if (direction == true) {
		scrollTimer = setTimeout("Start_Scroll_Images_Right()", 50);
	} else {
		scrollTimer = setTimeout("Start_Scroll_Images_Left()", 50);
	}
}

function Stop_Scroll_Images() {
	clearTimeout(scrollTimer);
}

function Scroll_Images(direction, scrollStep) {
	var ScrollContainer = document.getElementById("scrollImgContainer");
	var maxScroll = ScrollContainer.offsetWidth - ScrollContainer.parentNode.offsetWidth;
	
	if (direction == true) {
		if ((scrollPos+scrollStep) < maxScroll) { //check right boundary
			scrollPos += scrollStep;
			if (document.getElementById("ScrollLeftButton").src != "/images/ui/left_scroll.png") document.getElementById("ScrollLeftButton").src = "/images/ui/left_scroll.png";
		} else {
			scrollPos = maxScroll;
			document.getElementById("ScrollRightButton").src = "/images/ui/right_scroll_disabled.png";
		}
	} else {
		if ((scrollPos-scrollStep) > 0) { //check left boundary
			scrollPos -= scrollStep;
			if (document.getElementById("ScrollRightButton").src != "/images/ui/right_scroll.png") document.getElementById("ScrollRightButton").src = "/images/ui/right_scroll.png";
		} else {
			scrollPos = 0;
			document.getElementById("ScrollLeftButton").src = "/images/ui/left_scroll_disabled.png";
		}
	}
	ScrollContainer.style.left = "-" + scrollPos + "px";
}