function sort() {
	/* find the selected sort method */
	for (var i=0; i<document.sorter.method_selector.length; i++) {
		if (document.sorter.method_selector[i].checked) {
			var method = document.sorter.method_selector[i].value;
		}
	}
	
	if (method == 'lab') {
		/* sort by lab affiliation */
		location.href = 'directory_' + document.sorter.lab_menu.value + '.html';
	} else {
		/* sort by other requested method */
		location.href = 'directory_' + method + '.html';
	}
}