// Cross-Browser Functions



var dom = document.getElementById;

var iex = document.all;

var ns4 = document.layers;



function addEvent(event,method){

	this[event] = method;

	if(ns4) this.captureEvents(Event[event.substr(2,event.length).toUpperCase()]);

}

function removeEvent(event){

	this[event] = null;

	if(ns4) this.releaseEvents(Event[event.substr(2,event.length).toUpperCase()]);

}

function getElement(name,nest){

	nest = nest ? "document."+nest+"." : "";

	var el = dom ? document.getElementById(name) : iex ? document.all[name] : ns4 ? eval(nest+"document."+name) : false;

	el.css = ns4 ? el : el.style;

	el.getTop = function(){return parseInt(el.css.top) || 0};

	el.setTop = function(y){el.css.top = ns4 ? y: y+"px"};

	el.getHeight = function(){return ns4 ? el.document.height : el.offsetHeight};

	el.getClipHeight = function(){return ns4 ? el.clip.height : el.offsetHeight};

	el.hideVis = function(){el.css.visibility="hidden"};

	el.addEvent = addEvent;

	el.removeEvent = removeEvent;

	return el;

}

function getYMouse(e){

	return iex ? event.clientY : e.pageY;

}



document.addEvent = addEvent;

document.removeEvent = removeEvent;



// ||||||||||||||||||||||||||||||||||||||||||||||||||

// Scroller Class



ScrollObj = function(speed, dragHeight, trackHeight, trackObj, upObj, downObj, dragObj, contentMaskObj, contentObj){

	this.speed = speed;

	this.dragHeight = dragHeight;

	this.trackHeight = trackHeight;

	this.trackObj = getElement(trackObj);

	this.upObj = getElement(upObj);

	this.downObj = getElement(downObj);

	this.dragObj = getElement(dragObj);

	this.contentMaskObj = getElement(contentMaskObj);

	this.contentObj = getElement(contentObj,contentMaskObj);

	this.obj = contentObj+"Object";

	eval(this.obj+"=this");

	

	this.trackTop = this.dragObj.getTop();

	this.trackLength = this.trackHeight-this.dragHeight;

	this.trackBottom = this.trackTop+this.trackLength;

	this.contentMaskHeight = this.contentMaskObj.getClipHeight();

	this.contentHeight = this.contentObj.getHeight();

	this.contentLength = this.contentHeight-this.contentMaskHeight;

	this.scrollLength = this.trackLength/this.contentLength;

	this.scrollTimer = null;

	

	if(this.contentHeight <= this.contentMaskHeight){

		this.dragObj.hideVis();
		this.trackObj.hideVis();
		this.upObj.hideVis();
		this.downObj.hideVis();

	}else{

		var self = this;

		this.trackObj.addEvent("onmousedown", function(e){self.scrollJump(e);return false});

		this.upObj.addEvent("onmousedown", function(){self.scroll(self.speed);return false});

		this.upObj.addEvent("onmouseup", function(){self.stopScroll()});

		this.upObj.addEvent("onmouseout", function(){self.stopScroll()});

		this.downObj.addEvent("onmousedown", function(){self.scroll(-self.speed);return false});

		this.downObj.addEvent("onmouseup", function(){self.stopScroll()});

		this.downObj.addEvent("onmouseout", function(){self.stopScroll()});

		this.dragObj.addEvent("onmousedown", function(e){self.startDrag(e);return false});

		if(iex) this.dragObj.addEvent("ondragstart", function(){return false});

	}

}

ScrollObj.prototype.startDrag = function(e){

	this.dragStartMouse = getYMouse(e);

	this.dragStartOffset = this.dragObj.getTop();

	var self = this;

	document.addEvent("onmousemove", function(e){self.drag(e)});

	document.addEvent("onmouseup", function(){self.stopDrag()});

}

ScrollObj.prototype.stopDrag = function(){

	document.removeEvent("onmousemove");

	document.removeEvent("onmouseup");

}

ScrollObj.prototype.drag = function(e){

	var currentMouse = getYMouse(e);

	var mouseDifference = currentMouse-this.dragStartMouse;

	var dragDistance = this.dragStartOffset+mouseDifference;

	var dragMovement = (dragDistance<this.trackTop) ? this.trackTop : (dragDistance>this.trackBottom) ? this.trackBottom : dragDistance;

	this.dragObj.setTop(dragMovement);

	var contentMovement = -(dragMovement-this.trackTop)*(1/this.scrollLength);

	this.contentObj.setTop(contentMovement);

}

ScrollObj.prototype.scroll = function(speed){

	var contentMovement = this.contentObj.getTop()+speed;

	var dragMovement = this.trackTop-Math.round(this.contentObj.getTop()*(this.trackLength/this.contentLength));

	if(contentMovement > 0){

		contentMovement = 0;

	}else if(contentMovement < -this.contentLength){

		contentMovement = -this.contentLength;

	}

	if(dragMovement < this.trackTop){

		dragMovement = this.trackTop;

	}else if(dragMovement > this.trackBottom){

		dragMovement = this.trackBottom;

	}

	this.contentObj.setTop(contentMovement);

	this.dragObj.setTop(dragMovement);

	this.scrollTimer = window.setTimeout(this.obj+".scroll("+speed+")",25);

}

ScrollObj.prototype.stopScroll = function(){

	if(this.scrollTimer){

		window.clearTimeout(this.scrollTimer);

		this.scrollTimer = null;

	}

}

ScrollObj.prototype.scrollJump = function(e){

	var currentMouse = getYMouse(e);

	var dragDistance = currentMouse-(this.dragHeight/2);

	var dragMovement = (dragDistance<this.trackTop) ? this.trackTop : (dragDistance>this.trackBottom) ? this.trackBottom : dragDistance;

	this.dragObj.setTop(dragMovement);

	var contentMovement = -(dragMovement-this.trackTop)*(1/this.scrollLength);

	this.contentObj.setTop(contentMovement);

}



// ||||||||||||||||||||||||||||||||||||||||||||||||||

// Misc Functions



function fixNetscape4(){

	if(ns4origWidth != window.innerWidth || ns4origHeight != window.innerHeight){

		window.location.reload();

	}	

}

if(document.layers){

	ns4origWidth = window.innerWidth;

	ns4origHeight = window.innerHeight;

	window.onresize = fixNetscape4;

}



// ||||||||||||||||||||||||||||||||||||||||||||||||||



window.onload = function(){

	// speed, dragHeight, trackHeight, trackObj, upObj, downObj, dragObj, contentMaskObj, contentObj

	myScroll = new ScrollObj(6,25,450,"track","up","down","drag","contentMask","content");

	myScroll2 = new ScrollObj(6,21,164,"track2","up2","down2","drag2","contentMask2","content2");

	myScroll3 = new ScrollObj(6,21,75,"track3","up3","down3","drag3","contentMask3","content3");

	};