function initEventsWidget() {
	document.getElementById('conferences-tab').onclick = showConferences;
	document.getElementById('workshops-tab').onclick = showWorkshops;
	document.getElementById('events-tab').onclick = showEvents;
	showConferences();
}
function eventWidget() { return document.getElementById('events-widget'); }
function showConferences() { eventWidget().className = 'conferences'; }
function showWorkshops() { eventWidget().className = 'workshops'; }
function showEvents() { eventWidget().className = 'events'; }

if (window.addEventListener) window.addEventListener('load', initEventsWidget, false);
else if (window.attachEvent) window.attachEvent('onload', initEventsWidget);