function toggleFilter() {

	var filterEl = document.getElementById('filter');
	if (filterEl.className.indexOf('big')<0) {
		filterEl.className += ' big';
	} else {
		filterEl.className = filterEl.className.replace(/big/,'');
	}
}
function toggleNav() {

	var navEl = document.getElementById('nav1');
	if (navEl.className.indexOf('big')<0) {
		navEl.className += ' big';
	} else {
		navEl.className = navEl.className.replace(/big/,'');
	}
}