Projected Depreciation in Excel

[Suhail]

I have to calculate monthly projected depreciation in Excel. I am facing TWO problems


1. I want excel stop calculation of Depreciation, when book value is is zero. In the attached file at column AF, book value is zero and after this excel calculates depreciation which leads to negative book value.


2. I have to calculate the depreciation on asset which is going to be purchase in future. If an asset would be purchase in Dec-12, then its depreciation automatically starts from Dec-12 instead start calculation from Aug-12.

Sample file is attached.


Your assistance required.

Thanks

Sohail