function processItems(event, caller, containerId) {
	var container = document.getElementById(containerId);
	var itemsArray = container.getElementsByTagName('LI');

	// Reset all class names of list-items
	for (c = 0; c <= itemsArray.length; c++)	{
		if (itemsArray[c]) {
			itemsArray[c].className = '';
		}
	}

	// Set active list item
	caller.parentNode.className = 'active';
}