//Written by Nathan Faubion: http://n-son.com

//Use this or edit how you want, just give me

//some credit!

function jsScrollbar (o, s, a, ev) {

	var self = this;

	

	this.reset = function () {

		//Arguments that were passed

		this._parent = o;

		this._src    = s;

		this.auto    = a ? a : false;

		this.eventHandler = ev ? ev : function () {};

		//Component Objects

		this._up   = this._findComponent("Scrollbar-Up_reservas", this._parent);

		this._down = this._findComponent("Scrollbar-Down_reservas", this._parent);

		this._yTrack  = this._findComponent("Scrollbar-Track_reservas", this._parent);

		this._yHandle = this._findComponent("Scrollbar-Handle_reservas", this._yTrack);

		//Height and position properties

		this._trackTop = findOffsetTop(this._yTrack);

		this._trackHeight  = this._yTrack.offsetHeight;

		this._handleHeight = this._yHandle.offsetHeight;

		

		this._x = 0;

		this._y = 0;

		//Misc. variables

		this._scrollDist  = 5;

		this._scrollTimer = null;

		this._selectFunc  = null;

		this._grabPoint   = null;

		this._tempTarget  = null;

		this._tempDistX   = 0;

		this._tempDistY   = 0;

		this._disabled    = false;

		

		//alert(this._src.totalHeight);

		//alert(this._src.viewableHeight);

		

		this._ratio = (this._src.totalHeight - this._src.viewableHeight)/(this._trackHeight - this._handleHeight);

		

		this._yHandle.ondragstart  = function () {return false;};

		this._yHandle.onmousedown = function () {return false;};

		this._addEvent(this._src.content, "mousewheel", this._scrollbarWheel);

		this._removeEvent(this._parent, "mousedown", this._scrollbarClick);

		this._addEvent(this._parent, "mousedown", this._scrollbarClick);

		

		this._src.reset();

		with (this._yHandle.style) {

			top  = "0px";

			left = "0px";

		}

		this._moveContent();

		

		if (this._src.totalHeight < this._src.viewableHeight) {

			this._disabled = true;

			this._yHandle.style.visibility = "hidden";

			if (this.auto) this._parent.style.visibility = "hidden";

		} else {

			this._disabled = false;

			this._yHandle.style.visibility = "visible";

			this._parent.style.visibility  = "visible";

		}

	};

	this._addEvent = function (o, t, f) {

		if (o.addEventListener) o.addEventListener(t, f, false);

		else if (o.attachEvent) o.attachEvent('on'+ t, f);

		else o['on'+ t] = f;

	};

	this._removeEvent = function (o, t, f) {

		if (o.removeEventListener) o.removeEventListener(t, f, false);

		else if (o.detachEvent) o.detachEvent('on'+ t, f);

		else o['on'+ t] = null;

	};

	this._findComponent = function (c, o) {

		var kids = o.childNodes;

		for (var i = 0; i < kids.length; i++) {

			if (kids[i].className && kids[i].className == c) {

				return kids[i];

			}

		}

	};

	//Thank you, Quirksmode

	function findOffsetTop (o) {

		var t = 0;

		if (o.offsetParent) {

			while (o.offsetParent) {

				t += o.offsetTop;

				o  = o.offsetParent;

			}

		}

		return t;

	};

	this._scrollbarClick = function (e) {

		if (self._disabled) return false;

		

		e = e ? e : event;

		if (!e.target) e.target = e.srcElement;

		

		if (e.target.className.indexOf("Scrollbar-Up_reservas") > -1) self._scrollUp(e);

		else if (e.target.className.indexOf("Scrollbar-Down_reservas") > -1) self._scrollDown(e);

		else if (e.target.className.indexOf("Scrollbar-Track_reservas") > -1) self._scrollTrack(e);

		else if (e.target.className.indexOf("Scrollbar-Handle_reservas") > -1) self._scrollHandle(e);

		

		self._tempTarget = e.target;

		self._selectFunc = document.onselectstart;

		document.onselectstart = function () {return false;};

		

		self.eventHandler(e.target, "mousedown");

		self._addEvent(document, "mouseup", self._stopScroll, false);

		

		return false;

	};

	this._scrollbarDrag = function (e) {

		e = e ? e : event;

		var t = parseInt(self._yHandle.style.top);

		var v = e.clientY + document.body.scrollTop - self._trackTop;

		with (self._yHandle.style) {

			if (v >= self._trackHeight - self._handleHeight + self._grabPoint)

				top = self._trackHeight - self._handleHeight +"px";

			else if (v <= self._grabPoint) top = "0px";

			else top = v - self._grabPoint +"px";

			self._y = parseInt(top);

		}

		

		self._moveContent();

	};

	this._scrollbarWheel = function (e) {

		e = e ? e : event;

		var dir = 0;

		if (e.wheelDelta >= 120) dir = -1;

		if (e.wheelDelta <= -120) dir = 1;

		

		self.scrollBy(0, dir * 20);

		e.returnValue = false;

	};

	this._startScroll = function (x, y) {

		this._tempDistX = x;

		this._tempDistY = y;

		this._scrollTimer = window.setInterval(function () {

			self.scrollBy(self._tempDistX, self._tempDistY); 

		}, 40);

	};

	this._stopScroll = function () {

		self._removeEvent(document, "mousemove", self._scrollbarDrag, false);

		self._removeEvent(document, "mouseup", self._stopScroll, false);

		

		if (self._selectFunc) document.onselectstart = self._selectFunc;

		else document.onselectstart = function () { return true; };

		

		if (self._scrollTimer) window.clearInterval(self._scrollTimer);

		self.eventHandler (self._tempTarget, "mouseup");

	};

	this._scrollUp = function (e) {this._startScroll(0, -this._scrollDist);};

	this._scrollDown = function (e) {this._startScroll(0, this._scrollDist);};

	this._scrollTrack = function (e) {

		var curY = e.clientY + document.body.scrollTop;

		this._scroll(0, curY - this._trackTop - this._handleHeight/2);

	};

	this._scrollHandle = function (e) {

		var curY = e.clientY + document.body.scrollTop;

		this._grabPoint = curY - findOffsetTop(this._yHandle);

		this._addEvent(document, "mousemove", this._scrollbarDrag, false);

	};

	this._scroll = function (x, y) {

		if (y > this._trackHeight - this._handleHeight) 

			y = this._trackHeight - this._handleHeight;

		if (y < 0) y = 0;

		

		this._yHandle.style.top = y +"px";

		this._y = y;

		

		this._moveContent();

	};

	this._moveContent = function () {

		this._src.scrollTo(0, Math.round(this._y * this._ratio));

	};

	

	this.scrollBy = function (x, y) {

		this._scroll(0, (-this._src._y + y)/this._ratio);

	};

	this.scrollTo = function (x, y) {

		this._scroll(0, y/this._ratio);

	};

	this.swapContent = function (o, w, h) {

		this._removeEvent(this._src.content, "mousewheel", this._scrollbarWheel, false);

		this._src.swapContent(o, w, h);

		this.reset();

	};

	

	this.reset();

};