If you want a cron entry:
0 * * * * my_script then I recommend you think of a separate name for your cron management function, like, "cron_mgmt", whose first argument is a SWITCH in a CASE statement:
cron_mgmt () { case $1 in add ) ... ;; list ) ...;; remove ) ... help ) ... * ) echo "You need help. Here it is" cron_mgmt help ;; esac } 