JQuery :: Next / Previous Button For Every Scrollable Element

I'm trying to use the scrollTo plug in, maybe in the stupidest way, but I feel I am almost there!in my case every scrollable element has his own next-prev buttons, the script is able to extract a variable on the button click, id like to make him use it to calculate the position of the next-prev target. You can take a look to a live example at [URL].

Here's the script I've made:
$(document).ready(function () {
$('.triangolo_top, ') .click(function () {
var numero= $(this).attr('title');
$('#prova').text(numero)
$(window).scrollTo ('li:eq (+numero+1)', { duration:500, axis:'y'})
})});