calculating revenue over months
 

I have a sheet which looks like this

Vendor Start Date Revenue End Date
A 1-Mar-08 4000
B 15-Apr-08 10000
C 1-May-08 5000 1-Jun-08
D 1-May-08 5000 25-May-08

In the next columns what i would like to have is.......

Apr-08 May-08 June-08 Jul-08 (and so on)
4000 4000 4000 (since we are in Jun, Jul
would be blank)
(10000/30)*16 10000 10000
0 5000 0
0 (5000/31)*(25-1)

Can anyone help?