ThreeOhScroll.mo5 = navigator.userAgent.indexOf("Gecko") != -1
ThreeOhScroll.ie4 = navigator.appName == "Microsoft Internet Explorer" && document.all
ThreeOhScroll.ie5 = navigator.appName == "Microsoft Internet Explorer" && document.getElementById
ThreeOhScroll.pc = navigator.platform == "Win32"

// this number is for ie4 pc only - which cannot have the description box be of variable width (or atleast i can't figure out how to).
// you set the number of pixels that the desc tag will be permanently.
ThreeOhScroll.ie4pcDescWidth = 100

// i have no idea why this number is necessary, it just is. it is related to how far the scroller is from the top of the window
// in mozilla, but you will have to play with it to get it just right.
ThreeOhScroll.mozAdjust = ThreeOhScroll.mo5 ? 75 : 0

// this is how long it should take the scroller to animate when the user clicks a marker (in milliseconds)
ThreeOhScroll.aniLen = 250


function ThreeOhScroll(id)
{
	if (ThreeOhScroll.mo5 || (ThreeOhScroll.ie4 && ThreeOhScroll.pc) || ThreeOhScroll.ie5) {
		this.id = id
		this.getMembers()

		if (ThreeOhScroll.ie4 && !ThreeOhScroll.ie5 && ThreeOhScroll.pc) this.description.style.width = ThreeOhScroll.ie4pcDescWidth

		this.clipH		= parseInt(this.container.style.height)
		this.PTags		= ypGetDescendantsByTagName("P", this.content)
		var lastP		= this.PTags[this.PTags.length-1]
		var lastPTop	= lastP.offsetTop - ThreeOhScroll.mozAdjust
		this.docH		= lastPTop + Math.max(lastP.offsetHeight, this.clipH)
		this.scrollH	= this.docH - this.clipH
		this.thumbMax	= parseInt(this.thumbContainer.style.height) - this.thumbImg.height
		
		this.gRef = "ThreeOhScroll_"+id
		eval(this.gRef+"=this")
		this.thumb.obj	= this
		this.thumb.onmousedown = this.startDrag
		this.thumb.ondragstart = function() { return false }
	} else {
		alert ('The scroller won\'t work for your browser.\n\n Please get a newer one.')
	}
}

ThreeOhScroll.prototype.getMembers = function() {
	this.container=ypGetElementById('filterContainer');
	this.content=ypGetElementById('filterContent');
	this.thumb=ypGetElementById('filterThumb');;
	this.thumbImg=ypGetElementById('filterThumbImg');
	this.thumbContainer=ypGetElementById('filterThumbContainer');
	this.description=ypGetElementById('filterDescription');
}

ThreeOhScroll.prototype.startDrag = function(e) {
	if (!e) e = window.event
	var ey = e.pageY ? e.pageY : e.clientY
	this.dragLastY = ey
	this.dragStartOffset = ey - parseInt(this.style.top)
	ThreeOhScroll.current = this.obj
	document.onmousemove = this.obj.doDrag
	document.onmouseup = this.obj.stopDrag
	if (this.obj.aniTimer) window.clearInterval(this.obj.aniTimer)
	return false;
}

ThreeOhScroll.prototype.doDrag = function(e) {
	if (!e) e = window.event
	var obj = ThreeOhScroll.current
	var ey = (e.pageY ? e.pageY : e.clientY)
	var dy = ey - obj.thumb.dragLastY
	var ny = parseInt(obj.thumb.style.top) + dy
	if (ny >= obj.thumbMax) obj.thumb.dragLastY = obj.thumbMax + obj.thumb.dragStartOffset
	else if (ny < 0) obj.thumb.dragLastY = obj.thumb.dragStartOffset
	else obj.thumb.dragLastY = ey
	ny = Math.min(Math.max(ny, 0), obj.thumbMax)
	obj.jumpTo(ny * obj.scrollH / obj.thumbMax)
	return false;
}

ThreeOhScroll.prototype.stopDrag = function() {
	this.onmousemove = null
	this.onmouseup   = null
	//ThreeOhScroll.current.toggleThumb(0)
}


ThreeOhScroll.prototype.scroll = function() {
	var now = (new Date()).getTime()
	var elapsed = now - this.startTime
	if (elapsed > ThreeOhScroll.aniLen) this.endScroll()
	else {
		var t = ThreeOhScroll.aniLen - elapsed
		var ny = this.endPos - t * t * this.accel
		this.jumpTo(ny)
	}
}

ThreeOhScroll.prototype.endScroll = function() {
	this.jumpTo(this.endPos)
	this.arrow.style.top = this.endArrow
	this.aniTimer = window.clearInterval(this.aniTimer)
}

ThreeOhScroll.prototype.jumpTo = function(ny) {
	this.thumb.style.top	= Math.round(ny * this.thumbMax / this.scrollH)
	this.content.style.top	= -ny
}


function ypGetChildNodes(objParent) {
	return (objParent.childNodes ? objParent.childNodes : objParent.children)
}

function ypGetElementById(id) {
	return (document.getElementById ? document.getElementById(id) : document.all ? document.all[id] : false)
}

function ypGetDescendantsByTagName(sTag, objParent) {
	return (objParent.getElementsByTagName ? objParent.getElementsByTagName(sTag) : objParent.all && objParent.all.tags ? objParent.all.tags(sTag) : false)
}