Help with a date calculation

Below is the layout of my data. What I am trying to figure out is: If the
current month and year is not = to Col C, then Col E is 0, if it is = or
beyond, Col E should = $15,122 + Col F (Previous month). Example Date is now
Oct 09, so Col E is 0, on Nov 1, 09 Col E should be = to $15,122 + $2637.91.
I would like to apply this formula to Aug 09 - Jun 10 cells in Col E.

Hope this makes sense, and any help is much appreciated.

Col C Col D Col E Col F
Planned MTD Cost Monthly Budget Adjusted Balance
July 09 $14,872.07 $15,122.00 $249.93
Aug 09 $22,278.37 $15,371.93 $(6,906.44)
Sep 09 $5,601.07 $8,215.56 $2,614.49
Oct 09 $15,098.58 $17,736.49 $2,637.91
Nov 09 $- $- $-
Dec 09 $- $- $-
Jan 10 $- $- $-
Feb 10 $- $- $-
Mar 10 $- $- $-

No help needed was able to find a way to do what I needed.

Thanks for looking

"VinceW" wrote:

> Below is the layout of my data. What I am trying to figure out is: If the
> current month and year is not = to Col C, then Col E is 0, if it is = or
> beyond, Col E should = $15,122 + Col F (Previous month). Example Date is now
> Oct 09, so Col E is 0, on Nov 1, 09 Col E should be = to $15,122 + $2637.91.
> I would like to apply this formula to Aug 09 - Jun 10 cells in Col E.
>
> Hope this makes sense, and any help is much appreciated.
>
> Col C Col D Col E Col F
> Planned MTD Cost Monthly Budget Adjusted Balance
> July 09 $14,872.07 $15,122.00 $249.93
> Aug 09 $22,278.37 $15,371.93 $(6,906.44)
> Sep 09 $5,601.07 $8,215.56 $2,614.49
> Oct 09 $15,098.58 $17,736.49 $2,637.91
> Nov 09 $- $- $-
> Dec 09 $- $- $-
> Jan 10 $- $- $-
> Feb 10 $- $- $-
> Mar 10 $- $- $-
>