Activity type is not valid in current fiscal year

Dear All,

Q1. I have actvity type 1410 which is not assigned to cost center 4300.How to assign this activity type to cost center??

Q2. Actuvity type 1410, controlling area 1000, and cost center 4300 are not valid in fiscal year 2008. How to change these validity period?

Thanks & regards,

Sundar Desai