function openWindow(id)
{
	var div = document.getElementById(id);
	div.style.display = 'block';
}

function closeWindow(id)
{
	var div = document.getElementById(id);
	div.style.display = 'none';
}

function swapWindow(id)
{
	closeWindow('topic1');
	closeWindow('topic2');
	closeWindow('topic3');
	closeWindow('topic4');
	closeWindow('topic5');	
                closeWindow('topic6');
                
	
	openWindow(id);
}