Can't get previous element?

Question

I need to get the previous element of an element found by using "contains" - prev and prevAll('span') aren't working. Any ideas? Thanks!

<script>
    $(document).ready(function(){
        $("label:contains('Group')").prev().addClass("spMargin"); 
    });
</script>

<span class="radio"></span>
<label>Travel</label>

<span class="radio">(need to add class to this element!)</span>
<label>Group</label>

Answer 1

Using .prev() works for me. See http://jsfiddle.net/tT9Qu/