Fatal error: Uncaught Error: Call to undefined function

Fatal error: Uncaught Error: Call to undefined function ereg() in /public_html/wp-content/plugins/tantan-s3/wordpress-s3/class-plugin.php:77 Stack trace: #0 /public_html/wp-includes/class-wp-hook.php(298): TanTanWordPressS3Plugin->admin(”) #1 /public_html/wp-includes/class-wp-hook.php(323): WP_Hook->apply_filters(”, Array) #2 /public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #3 /public_html/wp-admin/admin.php(222): do_action(‘settings_page_t…’) #4 /public_html/wp-admin/options-general.php(10): require_once(‘…’) #5 {main} thrown in /public_html/wp-content/plugins/tantan-s3/wordpress-s3/class-plugin.php on line 77

Please help?