I have a jQuery array acting on each control having corresponding class:

function Foobar() {
   $('.foo').each(function() {
     // do something with $(this)
   }
}

I can access client-side controls like <input class="foo"> and server-side controls like asp:TextBox CassClass="foo">

But setting CssClass for asp:RadioButton doesn't make a sense. Here is generated code:

<span class="foo">
   <input type="radio" />
</span>

How to set class for inner input or another way gather it using jQuery?