var styleSheet = document.styleSheets[0];
var selector = 'ul.column ul';
var properties = 'display:none';

styleSheet.insertRule(selector + ' {' + properties + '}', styleSheet.cssRules.length);

//-----------------------

window.addEventListener('DOMContentLoaded', init, false);

//-----------------------

function init()
{
	var colLists = document.querySelectorAll('ul li ul');
	var hdrs = document.querySelectorAll('h2');
	var Z = hdrs.length-1;

	for (var i=Z; i>=0; i--)
		{
		hdrs[i].list = colLists[i];
		hdrs[i].addEventListener( 'click', toggle, false);
		}
}

function toggle()
{
	var list = this.list;

	if(list.className)
		{list.className = '';}
	else
		{list.className = 'expanded';}
}