Jquery selection

• Select several DOM element that are not of the same type
  This code select html but also body
  $('html, body');

• eq Return a given sub object by its index n°
  http://api.jquery.com/eq/

$('li').eq(2); // The third li

• $.merge() Allow to merge two things like 2 jquery objects
  http://api.jquery.com/jQuery.merge/

var previous = $(this).prev('td');   
var next = $(this).next('td');   
var all = $.merge(previous, next);   

• $('element').next(); Get the next element in a set of matched elements
  http://api.jquery.com/next/