uloszaminje on "[Plugin: Contact Form 7] Remove option from drop-down runtime"

I have this drop-down menu which contains numbers from 001 to 300.
After successful form submission, I'd like to remove selected drop-down option from database, so after all 300 users have submitted their data, all options from the list are removed.
I guess I should use add_action( 'wpcf7_mail_sent', 'your_wpcf7_mail_sent_function' ); routine, but how do I remove that option using PHP?
Thank you VERY MUCH in advance!

http://wordpress.org/plugins/contact-form-7/