US Payroll: Reversal of payroll result

Hi Experts,

Can anyone let me know how to go about this one.

Payroll has already run for December2008. Now I want to reverse this payroll run of Dec2008 in Jan2009. How can I do this ?

If Off-cycle payroll run is required, what are the paramenters to execute it ?

Thanks And Regards,

Somdeb Banerjee.