asset accounting very urgent!!!!!!

hi,

please i have an urgent issue!!!

I posted unplanned depreciation with ABAA- 640 in 9th month- 2007, but the depreciation for the rest of year 2007 is not recalculated, only begining with the next year!!! I need to be recalculated too for oct, nov, dec of 2007!!!

Example:

aquisition value= 100000

accumulated depr. = 20000

unplanned depr. = 10000

the net book value = 70000

I want the depreciation for octomber to be 70000/remaining life (in month).

How can I do this?