How do i create a query that will give me a cumulative total?

Question

I have a table with the following columns: reportDate DATETIME and losses CURRENCY and of course the ID column.

How do I write a query that will return a table with a running total of the losses column? Each date will have multiple entries so i think they will need use Sum() for each date. I know this has to do with the DSum function but im still lost on this one. It should look something like

Month   Losses   Cum
-----   ------   -----
Jan     $3,000   $3,000
Feb     $2,000   $5,000
Mar     $1,500   $6,500

Having a sql statement that's not Access specific would be the most help to me, I think. But all solutions are appreciated. Thanks for the help.