/**
 * Expands a day in the Festival Schedule page.
 * @param id Day identifier, as it is in the DOM.
 */
function expandDay(id){
    if (document.getElementById('day_schedule_' + id).style.maxHeight != '' && document.getElementById('day_schedule_' + id).style.maxHeight != '0em'){
        document.getElementById('day_schedule_' + id).style.maxHeight = '0em';
        setTimeout(function(){document.getElementById('slid_day_' + id).src = '/img/misc/slid-right.png';}, 500);
    }
    else{
        document.getElementById('day_schedule_' + id).style.maxHeight = 'initial';
        setTimeout(function(){document.getElementById('slid_day_' + id).src = '/img/misc/slid-down.png';}, 500);
    }
    document.getElementById('slid_day_' + id).style.opacity = '0';
    setTimeout(function(){document.getElementById('slid_day_' + id).style.opacity = '1';}, 500);
}