jQuery - auto focus textbox by Norlihazmey Ghazali
http://stackoverflow.com/questions/32430494/how-to-traverse-between-td-and-tr-element/32430682?noredirect=1#comment52726550_32430682
HTML
<table>
<tr>
<td>
<input class="inp" />
</td>
<td>
<input class="inp" />
</td>
</tr>
</table>
<button id="btn">Click me</button>
JavaScript
$('.inp').first().focus();
var all = $('.inp');
var index = (all.index(all.first()) + 1);
$('#btn').click(function () {
if (index == all.length) index = 0;
all.eq(index).focus();
index++;
});