final cut hd serial code

I've just moved my macbook over to the imac and upgraded the os t mountain loin.

Final cut HD is asking for my serial code but I have lost the box in the process of spring cleaning.

I can still access Final cut Hd on the macbook but the imac is asking for a serial code.

Can anyone help me as I would prefer to use final cut HD on the imac rather than just on the macbook.

I look forward to any help.

Andi