So fiddle

by kayen

HTML

<div id="petTest">
    <fieldset>
        <legend>Do you have a pet?</legend>
        <ul>
            <li><label for=""><input type="radio" name="petstatus" value="Yes" /> Yes</label></li>
            <li><label for=""><input type="radio" name="petstatus" value="No" /> No</label></li>
        </ul>
    </fieldset>
    
    <fieldset>
        <legend>Is it big?</legend>
        <ul>
            <li><label for=""><input type="radio" name="petsize" value="Yes" /> Yes</label></li>
            <li><label for=""><input type="radio" name="petsize" value="No" /> No</label></li>
        </ul>
    </fieldset>
    
    <fieldset>
        <legend>Is it a dog?</legend>
        <ul>
            <li><label for=""><input type="radio" name="pettype" value="Yes" /> Yes</label></li>
            <li><label for=""><input type="radio" name="pettype" value="No" /> No</label></li>
        </ul>
    </fieldset>
    <fieldset>
        <legend>Please note that dogs are not allowed at this event!</legend>
    </fieldset> 
</div>

JavaScript

$("#petTest fieldset")
    .hide()
    .eq(0).show()
    .end()
    .find("input[value='Yes']")
    .click(function() {
      $(this).parents("fieldset").next().show(300);
    })
    .end()
    .find("input[value='No']")
    .click(function() {
        $(this).parents("fieldset").nextAll().hide(300, function(){
            $(this).find("input").attr("checked", false);                
        });
    });