function get_obj(id) 
{
	try {
		return document.getElementById(id);
	}
	catch(e) {
		return null;
	}
	finally {
	};
}

function set_class(id, classname)
{
	try {
		get_obj(id).className = classname;
	}
	catch(e) {
	}
	finally {
	};
}