function swapVisibility(itemToMakeVisible, itemToMakeInvisible, visibleAttributeName) {
    if (itemToMakeVisible) itemToMakeVisible.style.display = ((visibleAttributeName == undefined || visibleAttributeName == null) ? 'block' : visibleAttributeName);
    if (itemToMakeInvisible) itemToMakeInvisible.style.display = 'none';
}