can't re-install Lion

Hi,

I had some problems with my macbook air 2008 so a apple support guy told me to re-install it.

I made a bootable hard drive and follow the instructions.

I reset my mac and the the Hdd didn't showed up, only the main osx system and the recovery hd.

I enter the recovery and deleted the computer hd, i started the system again but still no hdd only recovery HD.

Don't know what to do right now, i can't re-download it from the app store because when i got the Lion osx was already on it.

I need your help please.

Thanks