Jquery Tools: Scrollable - onBeforeSeek & onSeek toggle child div

Question

I'm scrolling some panels which contain some youtube clips using Jquery Tools Scrollable. I'd like to hide them during the transition to avoid a jerky animation.

Markup:

<div id="panel_items">
    <div id="wrap">
        <div class="event">
            <div class="header">Event 1</div><!-- Header is always displayed -->
            <div class="youtube">youtube clips</div><!-- hide during transition, then show -->
        </div>
        <div class="event">
            <div class="header">Event 2</div>
            <div class="youtube" style="display: none">More youtube clips</div>
        </div>
    </div>
</div>

Current JS:

$("#panel_items").scrollable({
    onBeforeSeek: function() { console.log("hide .child .youtube"); }, 
    onSeek: function() { console.log("Show child .youtube"); }      
});

Bonus question: How can I automatically set the height of #panel_items to match the current panel height (.event)?

Thank you.