Depreciation key forr 100% depreciation to be posted in 1st month

Dear All

The configuration of 100% deprecaition key in our system is like that it apportions the depreciation in 12 months..

My requirement is that the assets having value of Rs5000/- or less should be written off in the same year( which is an Income tax law)..

I want that these assets should be written off in the first month of acquisition itself or in any way they should get100% deprecaited in the same financial year..

Please guide me how to configure depreciation key for the same..

Regards

Ruby