function switchContent (file) {
	var frame = document.getElementById('mainContent');
	var li = document.getElementById(file);
	var buttonArea = document.getElementById('buttonArea');
	frame.src='/lachplesis/'+file+'.php';
	var lis = buttonArea.getElementsByTagName ('li');
	for (i=0;i<lis.length;i++) lis[i].className='';
	if (li) li.className='active';
	document.getElementById('comments').style.display='none';
}