Can't get jQuery UI radio buttons working

I'm trying to setup some jQuery UI radio buttons but it's not working.

jsFiddle

HTML

<div id="type_radios">
    <input type="radio" value="option_a" name="note_type" id="note_ty开发者_如何学JAVApe_option_a"/><label for="note_type_option_a">a</label>
    <input type="radio" value="option_b" name="note_type" id="note_type_option_b"/><label for="note_type_option_b">b</label>
</div>

Javascript

$(document).ready(function() {
   $("#type_radios").buttonset();
});

What am I doing wrong? Thanks for reading.

---

What you have works, you just aren't including the stylesheet for jQuery UI (and in this case there's just no visual change without it), for example:

http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/ui-lightness/jquery-ui.css

Here's your updated fiddle, stylesheet included, working :)