// vertical slider control
/*var slider1 = new Control.Slider( 'handle1', 'track1', {
								  axis: 'vertical',
								  onSlide: function(v) { scrollVertical(v, $('scrollable1'), slider1);  },
								  onChange: function(v) { scrollVertical(v, $('scrollable1'), slider1); }
});*/

/*var sliders = [];

for( i = 19; i < 25; i++ )
{
	sliders[i] = new Control.Slider( 'knob' + i, 'track' + i,
									 { axis: 'vertical',
									 onSlide: function( v ) { scrollVertical( v, $( 'slide' + i ), sliders[i]); },
									 onChange: function( v ) { scrollVertical( v, $( 'slide' + i ), sliders[i]); } } );
										 
	// disable vertical scrolling if text doesn't overflow the div
	if ($('slide' + i).scrollHeight <= $('slide' + i).offsetHeight)
	{
		sliders[i].setDisabled();
		$('slider' + i).hide();
	}
}*/

// 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));
}



$('slider15').style.display = 'block';
$('slider15').style.height = $('text_column15').offsetHeight + 'px';
$('track15').style.height = ($('text_column15').offsetHeight - 34) + 'px';
$('knob15').style.height = Math.round(($('text_column15').offsetHeight / $('text_column15').scrollHeight * $('track15').offsetHeight)) + 'px';

$('slider19').style.display = 'block';
$('slider19').style.height = $('text_column19').offsetHeight + 'px';
$('track19').style.height = ($('text_column19').offsetHeight - 34) + 'px';
$('knob19').style.height = Math.round(($('text_column19').offsetHeight / $('text_column19').scrollHeight * $('track19').offsetHeight)) + 'px';

$('slider24').style.display = 'block';
$('slider24').style.height = $('text_column24').offsetHeight + 'px';
$('track24').style.height = ($('text_column24').offsetHeight - 34) + 'px';
$('knob24').style.height = Math.round(($('text_column24').offsetHeight / $('text_column24').scrollHeight * $('track24').offsetHeight)) + 'px';



var slider15 = new Control.Slider( 'knob15', 'track15',
									 { axis: 'vertical',
									 onSlide: function( v ) { scrollVertical( v, $( 'text_column15' ), slider15); },
									 onChange: function( v ) { scrollVertical( v, $( 'text_column15' ), slider15); } } );
									 
var slider19 = new Control.Slider( 'knob19', 'track19',
									 { axis: 'vertical',
									 onSlide: function( v ) { scrollVertical( v, $( 'text_column19' ), slider19); },
									 onChange: function( v ) { scrollVertical( v, $( 'text_column19' ), slider19); } } );
									 
var slider24 = new Control.Slider( 'knob24', 'track24',
									 { axis: 'vertical',
									 onSlide: function( v ) { scrollVertical( v, $( 'text_column24' ), slider24); },
									 onChange: function( v ) { scrollVertical( v, $( 'text_column24' ), slider24); } } );
									 








/*slider1 = new Control.Slider( 'knob1', 'track1',
							  {
							  	axis: 'vertical',
							  	onSlide: function( v )
							  	{
							  		scrollVertical( v, $('slide1',*/