Showing Fatal error when try to create a filter

[Flens1]

Hi all,
I am using centOS, Apache my symfony version is 1.0.16
I want to create a filter according to http://www.symfony-project.org/book/1_0 ... er#Filters example but i am facing following error
Fatal error: Class 'rememberFilter' not found in /var/www/html/flens/cache/flens/dev/config/modules_search_config_filters.yml.php on line 14

Place give the suggestion.

Thanks