jQuery - change value of an input of the previous div

I have this kind of code :

function changeValue(el) {

}

<div class="tracklistOff">
    ...

    <div class="sideon">
        ...
    </div>

    <div class="trackon">
        ...
    </div>

    <div class="sideon">
        ...
    </div>

    <div class="trackon">
        ...
    </div>

    <div class="sideon">
        <span class="sideindex"><input type="hidden" name="sidesOriginal[]" value="#" /></span>
    </div>

    <div class="trackon">
        <span class="trackbotton"><a href="#" onClick="changeValue(this);return false">Edit</a></span>
    </div>

    <div class="sideon">
        ...
   开发者_StackOverflow社区 </div>

    <div class="trackon">
        ...
    </div>

    <div class="sideon">
        ...
    </div>

    <div class="trackon">
        ...
    </div>        

    ...
</div>

and i'd like to change the value of sidesOriginal[] to "hello" by clicking on Edit and using only the this reference as starting position. I'll change only that value, on the previous sideon, not for each sideon. How can I do it in jQuery?

Working example: http://jsfiddle.net/peeter/qy3h9/

$(this).parent().parent().children('.sideon').children('input[type="hidden"]').val('hello');