Searching for a simple first-child detection via javascript (no framework).

It should add some class for the first child of the element. Like a css-hacks for ie, but in javascript and for a html file.

Must work similar to :first-child

When I say no framework, I mean some code like this:

<script type="text/javascript">document.documentElement.id = "js"</script>

For example:

<div class="terms">
    <dl>
        <dt>Term 1 name</dt>
        <dd>Term 1 description</dd>
    </dl>
    <dl>
        <dt>Term 2 name</dt>
        <dd>Term 2 description</dd>
    </dl>
    <dl>
        <dt>Term 3 name</dt>
        <dd>Term 3 description</dd>
    </dl>
</div>

Three <dl>, the first one includes Term 1.

This css won't work in IE6, thats why I'm searching for a javascript solution. CSS-hacks are not allowed.

.terms dl:first-child { float: right; }