How to go over all inputs that have a custom attribute
<p>I have a form with checkboxes.
All of the checkboxes have an attribute called att, which contains several numbers that are separated by commas.</p>

<p>I'd like to create a function that gets a number, goes over all the checkboxes and checks all the checkboxes that their att attribute contains that number.</p>

<p>Can please someone point me at the right direction?</p>
