var Scroll2 = Class.create();
Object.extend(Scroll2, {
	build: function(object, speed) {
		object = $(object);
	
		var outer = $Class(object, "outer2");
		var inner = $Class(object, "inner2");
		var up = $Class(object, "up2");
		var barouter = $Class(object, "barouter2");
		var barinner = $Class(object, "barinner2");
		var down = $Class(object, "down2");
		
		if (!outer || !inner) return;
		var _textContainerHeight = outer.offsetHeight;
		var _textHeight = inner.offsetHeight;

		if (barouter) {
			var _barMaxHeight = barouter.offsetHeight - parseInt(Element.getStyle(barouter, "padding-top")) - parseInt(Element.getStyle(barouter, "padding-bottom"));
			var _barHeight = barinner.offsetHeight;

			var _maxOffsetTop = _textHeight - _textContainerHeight;
			var _maxBarTop = _barMaxHeight - _barHeight;

			Scroll2.repositionBar(object);
		}

		if (barouter) {
			Event.observe(document, 'mousemove', Mouse.FindMousePosition, false);
			iebody = document.documentElement ? document.documentElement : document.getElementsByTagName("body")[0];

			barinner.onmousedown = function(e) {
				var _barContainerTop = Position.cumulativeOffset(barouter)[1] + Math.abs(Mouse.y - Position.cumulativeOffset(barinner)[1] + (document.all ? iebody.scrollTop : 0));

				var f = function(e) {
					Scroll2._clearDocumentSelection();
					Mouse.FindMousePosition(e);

					var _dY = Mouse.y - _barContainerTop;
					_dY += document.all ? iebody.scrollTop : 0;

					if (_dY > _maxBarTop) _dY = _maxBarTop;
					if (_dY < 0) _dY = 0;

					var _y = _dY * _maxOffsetTop / _maxBarTop;
					_y = (_y > 0) ? _y : 0;

					outer.scrollTop = Math.round(_y);
					Element.setStyle(barinner, {"margin-top" : Math.round(_dY) + "px"});
					return true;
				}

				var g = function(e) {
					Event.stopObserving(document, 'mousemove', f, false);
					Event.stopObserving(document, 'mouseup', g, false);
				}

				Event.observe(document, 'mousemove', f, false);
				Event.observe(document, 'mouseup', g, false);
			};

			barinner.mouseup = function () {
				Event.stopObserving(document, 'mousemove', function() {}, false);
				Event.stopObserving(document, 'mouseup', function() {}, false);
			};
		}

		var fixedScroll = function (d) {
			outer.scrollTop = outer.scrollTop + d * speed;

			if (barinner) {
				var _dY = outer.scrollTop * _maxBarTop / _maxOffsetTop;
				_dY = Math.round(_dY);
				if (_dY > _maxBarTop) _dY = _maxBarTop;
				if (_dY < 0) _dY = 0;
				Element.setStyle(barinner, { "margin-top": _dY + "px" });
			}
		};

		if (up) {
			up.onmousedown = function () {
				if (up._t) clearInterval(up._t);
				if (down._t) clearInterval(down._t);
				up._t = setInterval(function() { fixedScroll(-1); }, 100);
			};

			up.onmouseup = function () {
				if (up._t) clearInterval(up._t);
			};

			up.onmouseout = function () {
				if (up._t) clearInterval(up._t);
			};
		}

		if (down) {
			down.onmousedown = function () {
				if (up._t) clearInterval(up._t);
				if (down._t) clearInterval(down._t);
				down._t = setInterval(function() { fixedScroll(1); }, 100);
			};

			down.onmouseup = function () {
				if (down._t) clearInterval(down._t);
			};

			down.onmouseout = function () {
				if (down._t) clearInterval(down._t);
			};
		}
	},

	repositionBar: function(object) {
		object = $(object);

		var outer = $Class(object, "outer2");
		var inner = $Class(object, "inner2");
		var barouter = $Class(object, "barouter2");
		var barinner = $Class(object, "barinner2");

		var _textContainerHeight = outer.offsetHeight;
		var _textHeight = inner.offsetHeight;
		var _barMaxHeight = barouter.offsetHeight - parseInt(Element.getStyle(barouter, "padding-top")) - parseInt(Element.getStyle(barouter, "padding-bottom"));
		var _barHeight = barinner.offsetHeight;

		var _maxOffsetTop = _textHeight - _textContainerHeight;
		var _maxBarTop = _barMaxHeight - _barHeight;

		outer.scrollTop = outer.scrollTop > _maxOffsetTop ? _maxOffsetTop : outer.scrollTop;
		var _dY = _maxBarTop * outer.scrollTop / _maxOffsetTop;
		if (_dY > _maxBarTop) _dY = _maxBarTop;
		Element.setStyle(barinner, {"margin-top" : Math.round(_dY) + "px"});
	},

	/* <ClearSealections> */ 
	_clearDocumentSelection: function() {
		if (document.selection)	{
			if (document.selection.clear) document.selection.clear();
			else if (document.selection.empty) document.selection.empty();
		} else {
			if (window.getSelection) {
				try{
					window.getSelection().collapse();
					window.getSelection().removeAllRanges();
				} catch(e) { };
			}
		}
	}
	/* </ClearSealections> */ 
});