var lastElementId = null;

function showElement(id) {
    if (lastElementId != null) {
        $("#" + lastElementId).hide();
    }

    lastElementId = id;
    $("#" + id).show();
    $("#balloon_" + id).hide();
}

function showVideo(sourceMedia, containerId) {
    $("#" + containerId).attr("src", sourceMedia);
}