How do you put another product key into existing Norton account?

Hi Guys

I have an existing Norton account which I got through using Norton 360,Any way I could not use Norton 360 and got it refunded.I went to a shop they installed NIS2008 for me,I have since up graded to NIS2009 with no problems,I have the product key at home but how can I add it to my existing Norton account as the only key in there is the refunded 360 which has been deactivated(checked with Tony in forum feedback)Any ideas or can I close the account as there is no use for it??