If/And/Vlookup question

Hi all,

I have a spreadsheet set up as follows:
Column A = dates in month/day/year format
Column E = number of hours
Column F = $ rate associated with the hours in Column E
Column I = Total of Column E X Column F

In Column J I would like to do the following, but I'm not sure what's the most efficient way of doing it. I would like to summarize the Total amount in Column I for each month and year. For example, I would like to add the totals from Column I for all the data for the month of May, 2004 (dates in Column A). I understand I can add a row under each each month and subtotal the months that way, but I would prefer to do this seperate from the original data in Columns A-I.

Is this possible?

Thanks!