I want to switch my Adobe programs from my old Mac to my new Mac but the serial number wont work when I put it in!

I bought the Adobe Premiere Suite 5.5 a couple years ago and I recently bought a new Mac. I have lost the CD but I still have the serial number, When I went to put my programs on my new Mac they said the serial number wouldnt work. I am just wondering if there is way I can move the programs over? My classes are starting soon and I'm getting a bit nervous!

-Maria