var	upH = 15; // Height of up-arrow
var	upW = 18; // Width of up-arrow
var	downH = 15; // Height of down-arrow
var	downW = 18; // Width of down-arrow
var	dragH = 56; // Height of scrollbar
var	dragW = 18; // Width of scrollbar
var	scrollH = 262; // Height of scrollbar
var	speed = 5; // Scroll speed

// And now... go to the bottom of the page...

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

var	mouseY; // Mouse Y position onclick
var	mouseX; // Mouse X position onclick

var	clickUp = false; // If click on up-arrow
var	clickDown = false; // If click on down-arrow
var	clickDrag = false; // If click on scrollbar
var	clickAbove = false; // If click above scrollbar
var	clickBelow = false; // If click below scrollbar

var	timer = setTimeout("",800); // Repeat variable
var	upL; // Up-arrow X
var	upT; // Up-arrow Y
var	downL; // Down-arrow X
var	downT; // Down-arrow Y
var	dragL; // Scrollbar X
var	dragT; // Scrollbar Y
var	rulerL; // Ruler X
var	rulerT; // Ruler Y
var	contentT; // Content layer Y;
var	contentH; // Content height
var	contentClipH; // Content clip height
var	scrollLength = 359; // Number of pixels scrollbar should move
var	startY; // Keeps track of offset between mouse and span

picup = new Image();    picup.src = "up.gif";
picdown	= new Image();  picdown.src = "down.gif";
picdrag	= new Image();  picdrag.src = "drag.gif";

// Preload
function eventLoader(){
	if(ie4){
					// Up-arrow X and Y variables
			upL = document.all.up.style.pixelLeft;
			upT = document.all.up.style.pixelTop;           
			// Down-arrow X and Y variables
			downL = document.all.down.style.pixelLeft;
			downT = document.all.down.style.pixelTop;
			// Scrollbar X and Y variables
			dragL = document.all.drag.style.pixelLeft;
			dragT = document.all.drag.style.pixelTop;               
			// Ruler Y variable
			rulerT = document.all.ruler.style.pixelTop;             
			// Height of content layer and clip layer
			contentH = document.all.content.offsetHeight;
			contentClipH = document.all.contentClip.offsetHeight;
	}
	else if(nn4){
			// Up-arrow X and Y variables
			upL = document.up.left;
			upT = document.up.top;          
			// Down-arrow X and Y variables
			downL = document.down.left;
			downT = document.down.top;              
			// Scrollbar X and Y variables
			dragL = document.drag.left;
			dragT = document.drag.top;              
			// Ruler Y variable
			rulerT = document.ruler.top;
			// Height of content layer and clip layer
			contentH = document.contentClip.document.content.clip.bottom;
			contentClipH = document.contentClip.clip.bottom;
	}
	else if(dom){
			// Up-arrow X and Y variables
			upL = parseInt(document.getElementById("up").style.left);
			upT = parseInt(document.getElementById("up").style.top);
			// Down-arrow X and Y variables
			downL = parseInt(document.getElementById("down").style.left);
			downT = parseInt(document.getElementById("down").style.top);
			// Scrollbar X and Y variables
			dragL = parseInt(document.getElementById("drag").style.left);
			dragT = parseInt(document.getElementById("drag").style.top);
			// Ruler Y variable
			rulerT = parseInt(document.getElementById("ruler").style.top);
			// Height of content layer and clip layer
			contentH = document.getElementById("content").offsetHeight;
			contentClipH = document.getElementById("contentClip").offsetHeight;
			document.getElementById("content").style.top = 0 + "px";
			
	}
	// Number of pixels scrollbar should move
	scrollLength = ((scrollH-dragH)/(contentH-contentClipH));
	// Initializes event capturing
	if(nn4){
			document.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP)
			window.onresize = reloadPage;
	}
	document.onmousedown = down;
	document.onmousemove = move;
	document.onmouseup = up;
}

// Mousedown
function down(e){
	if((document.layers && e.which!=1) || (document.all && event.button!=1)) return true; // Enables the right mousebutton          
	getMouse(e);
	startY = (mouseY - dragT);
	
	// If click on up-arrow
	if(mouseX >= upL && (mouseX <= (upL + upW)) && mouseY >= upT && (mouseY <= (upT + upH))){
			clickUp = true;
			//picDown('up');
			return scrollUp();
	}       
	// Else if click on down-arrow
	else if(mouseX >= downL && (mouseX <= (downL + downW)) && mouseY >= downT && (mouseY <= (downT + downH))){
			clickDown = true;
			//picDown('down');
			return scrollDown();
	}
	// Else if click on scrollbar
	else if(mouseX >= dragL && (mouseX <= (dragL + dragW)) && mouseY >= dragT && (mouseY <= (dragT + dragH))){
			clickDrag = true;
			//picDown('drag');
			return false;
	}
	else if(mouseX >= dragL && (mouseX <= (dragL + dragW)) && mouseY >= rulerT && (mouseY <= (rulerT + scrollH))){
			// If click above drag
			if(mouseY < dragT){
					clickAbove = true;
					clickUp = true;
					return scrollUp();
			}
			// Else click below drag
			else{
					clickBelow = true;
					clickDown = true;
					return scrollDown();
			}
	}
	// If no scrolling is to take place
	else{
			return true;
	}
}

function picDown(which){
	if(document.all) {
			eval('document.all.pic' + which + '.src = pic' + which + '.src');
	}
	else {
			eval('document.' + which + '.document.pic' + which + '.src = pic' + which + '.src');
	}
}

function picUp(which){
	if(document.all) {
			eval('document.all.pic' + which + '.src = "' + which + '.gif"');
	}
	else {
			eval('document.' + which + '.document.pic' + which + '.src = "' + which + '.gif"');
	}
}

// Drag function
function move(e){
	if(clickDrag && contentH > contentClipH){
			getMouse(e);
			dragT = (mouseY - startY);
			
			if(dragT < (rulerT))
					dragT = rulerT;         
			if(dragT > (rulerT + scrollH - dragH))
					dragT = (rulerT + scrollH - dragH);
			
			contentT = ((dragT - rulerT)*(1/scrollLength));
			contentT = eval('-' + contentT);

			moveTo();
	}
	// So ie-pc doesn't select gifs
	if(ie4)
			return false;
}

function up(){
	clearTimeout(timer);
	// Resetting variables
	clickUp = false;
	clickDown = false;
	clickDrag = false;
	clickAbove = false;
	clickBelow = false;
	//picUp('up');
	//picUp('down');
	//picUp('drag');
	return true;
}

// 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);
}

// Reads mouse X and Y coordinates
function getMouse(e){
	if(ie4){
			mouseY = event.clientY;
			mouseX = event.clientX;
	}
	else if(nn4 || dom){
			mouseY = e.pageY;
			mouseX = e.pageX;
	}
}

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

// Scrolls up
function scrollUp(){
	getT();
	
	if(clickAbove){
			if(dragT <= (mouseY-(dragH/2)))
					return up();
	}
	
	if(clickUp){
			if(contentT < 0){
					dragT = dragT - (speed*scrollLength);
					
					if(dragT < (rulerT))
							dragT = rulerT;
							
					contentT = contentT + speed;
					if(contentT > 0)
							contentT = 0;
					
					moveTo();
					timer = setTimeout("scrollUp()",25);
			}
	}
	return false;
}

// Scrolls down
function scrollDown(){
	getT();
	
	if(clickBelow){
	
			if(dragT >= (mouseY-(dragH/2)))
					return up();
	}

	if(clickDown){
		if(contentT > -(contentH - contentClipH)){                      

			dragT = dragT + (speed*scrollLength);
			if(dragT > (rulerT + scrollH - dragH))
					dragT = (rulerT + scrollH - dragH);
			
			contentT = contentT - speed;
			if(contentT < -(contentH - contentClipH))
					contentT = -(contentH - contentClipH);
			
			moveTo();
			timer = setTimeout("scrollDown()",25);
		}
	}
	return false;
}

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