function addLessonPlanHandlers() {
    // add animations
    // TODO: add slide open animation (but how to determine final height and do we want to side all content down below?)
    
    // add mouse handlers
    // TODO: do this here instead of inline with content
/*
    for (var i = 1; i <= 3; i++)
    {
        YAHOO.util.Event.addListener(document.getElementById('lp_' + i + '_h'), "click", showHideLessonPlans); 
    }
*/
}
YAHOO.util.Event.onContentReady('LessonPlans', addLessonPlanHandlers, this);


/**
 * Toggles the topic list for a grade level on the front page center Lesson Plans section
 * @param integer whichOne switch to this grade level
 * @todo // TODO: change to use above event handlers and e instead of whichOne
 */
function showHideLessonPlans(whichOne) {
    //var header = document.getElementById('lp_' + whichOne + '_h');
    var image = document.getElementById('lp_' + whichOne + '_i');
    var content = document.getElementById('lp_' + whichOne + '_c');
    if (content.style.display == 'none')
    {
        //header.style.backgroundImage = 'url(images/lessonplans_collapse-trans.png)';
        image.src = 'images/lessonplans_collapse-trans.png';
        content.style.display = 'block';
    }
    else
    {
        //header.style.backgroundImage = 'url(images/lessonplans_expand-trans.png)';
        image.src = 'images/lessonplans_expand-trans.png';
        content.style.display = 'none';
    }
}