function toggleFabric() {
	if(fab.style.visibility == "visible") {
		fab.setStyle('opacity', 0);
	} else {
		fab.setStyle('opacity', 1);
	}
}

function getElementsByClass(elem, classname) {
    classes = new Array();
    alltags = document.getElementsByTagName(elem);
    for (i=0; i<alltags.length; i++)
        if (alltags[i].className == classname)
            classes[classes.length] = alltags[i];
    return classes;
}

function setSelectedNav(sel) {
	var sn = document.getElementById(sel);
	var coll = $('categories').getElements('li');
	var len = coll.length;
	for(var i=0;i<len;++i) {
		coll[i].setAttribute("class","");
		coll[i].setAttribute("className","");
		
	}
	sn.setAttribute("class", "active");
	sn.setAttribute("className", "active");
}