var upH = 13; // Height of up-arrow
var upW = 14; // Width of up-arrow
var downH = 13; // Height of down-arrow
var downW = 14; // Width of down-arrow
var dragH = 58; // Height of scrollbar
var dragW = 14; // Width of scrollbar
var scrollH = 216; // Height of scrollbar
var speed = 4; // Scroll speed

// Browser detection
var dom = document.getElementById ? true:false;
var nn4 = document.layers ? true:false;
var ie4 = document.all ? true:false;

var timer = setTimeout("",500); // Repeat variable
var contentT; // Content layer Y;
var contentH; // Content height
var contentClipH; // Content clip height
var startY; // Keeps track of offset between mouse and span


// Reads content layer top
function getT(){
	if(ie4)
		contentT = document.all.content.style.pixelTop;
	else if(nn4)
		contentT = document.contentClip.document.content.top;
	else if(dom)
		contentT = parseInt(document.getElementById("content").style.top);
}


// Moves the layer
function moveTo(){
	if(ie4){
		document.all.content.style.top = contentT;
	}
	else if(nn4){
		document.contentClip.document.content.top = contentT;
	}
	else if(dom){
		document.getElementById("content").style.top = contentT + "px";
	}
}

// Scrolls up
function scrollUp(){
	if(contentT < 0){					
			contentT = contentT + speed;
			if(contentT > 0)
				contentT = 0;
			
			moveTo();
	}
	timer = setTimeout("scrollUp()", 1);
//	return false;
}

// Scrolls down
function scrollDown(){
	getT();
	
	if(contentT > -(contentH - contentClipH)){			
		contentT = contentT - speed;
		if(contentT < -(contentH - contentClipH))
			contentT = -(contentH - contentClipH);
		moveTo();
	}
	timer = setTimeout("scrollDown()", 1);
//	return false;
}

function stopScroll(){
	clearTimeout(timer);
}

// reloads page to position the layers again
function reloadPage(){
	location.reload();
}

function updateHeight() {
	if(dom) {
		contentH = parseInt(document.getElementById("content").offsetHeight);
	}
	else if(ie4) {
		contentH = parseInt(document.all.content.scrollHeight);
	}
	else if(nn4) {
		contentH = document.contentClip.document.content.clip.bottom;
	}
}

function getImage(layer, name) {
	var img;
	if(dom) {
		img = document.getElementById(name);
	}
	else if(ie4) {
		img = document.images[name];
	}
	else if(nn4) {
		img = eval('document.layers["' + layer + '"].document.images["' + name + '"]');
	}
	else img = 0;
	
	return img;
}	

// Preload
function eventLoader(){
	if(ie4){
		contentH = parseInt(document.all.content.scrollHeight);
		contentClipH = parseInt(document.all.contentClip.style.height);
	}
	else if(nn4){
		contentH = document.contentClip.document.content.clip.bottom;
		contentClipH = document.contentClip.clip.bottom;
	}
	else if(dom){
		contentH = parseInt(document.getElementById("content").offsetHeight);
		contentClipH = parseInt(document.getElementById("contentClip").offsetHeight);
		document.getElementById("content").style.top = 0 + "px";
	}
}