function chcss (newcss) {
	clearallli ();
	document.getElementById('css').href = 'css/stylesheet' + newcss + '.css';
	document.getElementById('li_' + newcss).style.fontWeight = 'bold';
}

function clearallli () {
	
	var maxli = document.getElementById('maxli').value;
	
	for (i=1; i<= maxli; i++) {
		document.getElementById('li_' + i).style.fontWeight = 'normal';
	}
}