var activeEventID = ''; 

function showEvent(IdName) { 
	if (activeEventID != '')
		document.getElementById(activeEventID).style.display = 'none'; 
		
	if (activeEventID != IdName) { 
		document.getElementById(IdName).style.display = 'block'; 
		activeEventID = IdName; 
	} 
	else 
		activeEventID = ''; 
		
}