// vertical slider control
var slider = new Control.Slider('handle', 'track', {
	axis: 'vertical',
	onSlide: function(v) { scrollVertical(v, $('scrollable'), slider);  },
	onChange: function(v) { scrollVertical(v, $('scrollable'), slider); }
});


// 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));
}

// disable vertical scrolling if text doesn't overflow the div
if ($('scrollable').scrollHeight <= $('scrollable').offsetHeight) {
	slider.setDisabled();
	$('track').hide();
	$('sliderUp').hide();
	$('sliderDown').hide();	
}

function sliderArrowClick(dir)
{
	if(dir == 1)
	{
		//slider value decrease, min 0
		if(slider.value != 0)
		{
			slider.setValue(slider.value -0.05);
		}
	}
	else if(dir == -1)
	{
		//slider value increase, max 6
		if(slider.value != 6)
		{
			slider.setValue(slider.value + 0.05);
		}
	}
}