I have an active adwords account. Recently i used a $25 voucher ( from Hostgator ) and they charged $5 for activation and gave me $20 as credit. Now when i am trying to add funds in to get my ad running, adwords do not allow me to add funds using credit balalance. I have $20 credit in my account but adsense is still asking for adding funds. now tell me what can i do now?