// vertical slider control
var slider4 = new Control.Slider('handle4', 'track4', {
	axis: 'vertical',
	onSlide: function(v) { scrollVertical(v, $('blogslist'), slider4);  },
	onChange: function(v) { scrollVertical(v, $('blogslist'), slider4); }
});
			
// scroll the element vertically based on its width and the slider maximum value
function scrollVertical(value, element, slider) {
	element.scrollTop = Math.round(value/slider.maximum*(element.scrollHeight-element.offsetHeight));
}

	//alert($('blogslist').scrollHeight);
	//alert($('blogslist').offsetHeight);
// disable vertical scrolling if text doesn't overflow the div
if ($('blogslist').scrollHeight <= $('blogslist').offsetHeight) {
	slider4.setDisabled();
	$('wrap4').hide();
}						

//Clicking on top and bottom arrows will move up and down
function moveUp(event) {
	slider4.setValueBy(-0.1);
}
function moveDown(event) {
	slider4.setValueBy(0.1);
}			
Event.observe('track-top4', 'click', moveUp);
Event.observe('track-bottom4', 'click', moveDown);

// mouse wheel code from http://adomas.org/javascript-mouse-wheel/
function handle4(delta) {
	slider4.setValueBy(-delta/10);
}
			
/** Event handler for mouse wheel event. */
function wheel4(event){
	var delta = 0;
	if (!event) /* For IE. */
		event = window.event;
	if (event.wheelDelta) { /* IE/Opera. */
		delta = event.wheelDelta/120;
		/** In Opera 9, delta differs in sign as compared to IE. */
		/*if (window.opera)
			delta = -delta;*/
	} else if (event.detail) { /** Mozilla case. */
		/** In Mozilla, sign of delta is different than in IE.
		* Also, delta is multiple of 3.
		*/
		delta = -event.detail/3;
	}

	/** If delta is nonzero, handle it.
	* Basically, delta is now positive if wheel was scrolled up,
	* and negative, if wheel was scrolled down.
	*/
	if (delta)
		handle4(delta);

	/** Prevent default actions caused by mouse wheel.
	* That might be ugly, but we handle scrolls somehow
	* anyway, so don't bother here..
	*/
	if (event.preventDefault)
		event.preventDefault();
	
	event.returnValue = false;
}

// mozilla
Event.observe('blogslist', 'DOMMouseScroll', wheel4);

// IE/Opera
Event.observe('blogslist', 'mousewheel', wheel4);