[jQuery] Accordion activate not working

[KCWebMonkey]

I have an accordion which i am trying to activate on page load, and
the .activate function doesn't appear to be working. can someone show
me how i'm implementing it incorrectly?

JavaScript:

        $(document).ready(function() {
                $('#childnav').accordion({
                        autoheight: false,
                        header: '.toggle',
                        event: 'click',
                        alwaysOpen: true,
                        active: false
                });

                $(".toggle").activate(0);
        });

HTML:

<ul id="childnav">
        <li id="childnav_about">
                <div style="width:277px;height:5px;background:#014F75;"></div>
                <a href="#" class="toggle"><span>About Us</span></a>
                <ul class="childnav_sub">
                        <li><a href="#">Link 1</a></li>
                        <li><a href="#">Link 2</a></li>
                </ul>
        </li>
        <li id="childnav_homes">
                <img src="/images/childnav_spacer.jpg" alt="" />
                <a href="#" class="toggle"><span>New Homes</span></a>
                <ul class="childnav_sub">
                        <li><a href="#">another link</a></li>
                        <li><a href="#">another link</a></li>
                </ul>
        </li>
        <li id="childnav_community">
                <img src="/images/childnav_spacer.jpg" alt="" />
                <a href="#" class="toggle"><span>The Community</span></a>
                <ul class="childnav_sub">
                        <li><a href="#">Arial PhotoGraph</a></li>
                        <li><a href="#">Amenities</a></li>
                        <li><a href="#">Schools</a></li>
                        <li><a href="#">Utilities</a></li>
                </ul>
        </li>
        <li id="childnav_news">
                <img src="/images/childnav_spacer.jpg" alt="" />
                <a href="#" class="toggle"><span>News &amp; Events</span></a>
                <ul class="childnav_sub">
                        <li><a href="#">Link 1</a></li>
                        <li><a href="#">Link 2</a></li>
                        <li><a href="#">Link 1</a></li>
                        <li><a href="#">Link 2</a></li>
                        <li><a href="#">Link 1</a></li>
                        <li><a href="#">Link 2</a></li>
                </ul>
        </li>
        <li id="childnav_contact">
                <img src="/images/childnav_spacer.jpg" alt="" />
                <a href="#" class="toggle"><span>Contact Us</span></a>
                <ul class="childnav_sub">
                        <li><a href="#">Link 1</a></li>
                        <li><a href="#">Link 2</a></li>
                        <li><a href="#">Link 1</a></li>
                </ul>
        </li>
</ul>