n(e){
		slider_down = false;
	}, false);

	slider.addEventListener('pointerup', function(e){
		slider_down = false;
	}, false);

	slider.addEventListener('pointerdown', function(e){
		slider_down = true;
		position_slider(no, e.clientX);
		draw_slider(no);
		slider.releasePointerCapture(e.pointerId);
	}, false);

	slider.addEventListener('pointermove', function(e){
		if(slider_down){
			position_slider(no, e.clientX);
			draw_slider(no);
		}
	}, false);
}

function draw_slider(no){
	ctx = document.getElemen