function flip (the_ids, c1, c2) {
	var b = "";
	var a = the_ids.split(', ');
	for (var j = 0; j < a.length; j++) {
		b = a[j];
		var target_id = window.document.getElementById(b);
		if (target_id.className == c1) {
			target_id.className = c2;
		} else {
			target_id.className = c1;
		}
	}
	return (false);
}