Upgrade to Parallels 6 without installed version 5

Hallo everybody,

i have a license of Parallels 5 but which at the moment is not installed on my Mac. Now i upgraded to Lion and wanted to use my Parallels Desktop again. When I tried to install version 5 i got the message that it is not compatible with Mac OS Lion and i couldn't install the software. I'm a bit pissed that I have to upgrade but ok i accepted this by now.

But my question is now how can i get the Upgrade to Version 6 without my version 5 being currently installed?? I don't wan't to buy the full license for 80$.

Can somebody help me on this??