How to add events on Jquery UI button

How to add events on Jquery UI button

I have a question on how to use Jquery UI.
This is my first time that I try Jquery UI and I could add a button by
using Jquery UI button.
Now, I'd like to add events when the radio is switched on and off.
How could I add events to Jquery UI button?
Thanks in advance !!
output

javascript
$(function(){
$('input[type=radio]').button();
$('.set').buttonset();
})
html
<div class="set">
<input type="radio" name="radio" id="radio1"><label for="radio1"
/>ON</label>
<input type="radio" name="radio" id="radio2"><label for="radio2"
/>OFF</label>
</div>