Never expiring listings in directory

Hello out there
I am collecting Listings from Companies even for free. When i create a Listing Package, i have to fill in some datas, how Long this Listing will be alive.
Is there a possibility to Switch Listings to “endless” for to kill the “Count Down Window” on each Listing?
Many Thanks for every hint, and Sorry for my bad English
(I am from Austria <Europe>)

Yours sincerely Thomas
http://www.raucherzone.net