Treatment of Customer Advance (100%) and subsequently recognize Revenue

Hi Dears,

My client requirement is as follows:-

Customer pays us Advance amount (100%) in the beginning of year for 12 months . Subsequently  it is required to have 12 monthly invoices of equal amount to recognize the revenue.

Accounting "

  Cash ---- 12,000

  Unearned Revenue ---- 12,000

  (for Cash received in advance)

Unearned Revenue ---- 1,000

     Revenue-------------------1,000

(Monthly Invoices to recognize revenue)

Any help to achieve this requirement.

Thanks