if (document.getElementById && document.createElement)
    {
        var objMenu = document.getElementById('leftnav');
        var objNested = objMenu.getElementsByTagName('ul');
		
        for (var i=0; i<objNested.length; i++)
        {
	      if (objNested[i].parentNode.className == sub){
		  objNested[i].style.display = 'block';}
        }
    }