public static boolean class_exists(String classname,boolean loadClass) {
		String key = "!" + classname + "!";
		if (classes.matches(key)) {
			return true; 
		}
		if (noClasses.matches(key)) {
			return false;
		}
		boolean exists = false;
		
		Utils u = new Utils();
		exists = u.class_exists(classname);
		if (exists) {
			if (!classes.matches(key)) classes = classes + key;
		} else {
			if (!noClasses.matches(key)) noClasses = noClasses + key;
		}
		return exists;
	}