Sum values that precede todays date

[traineeross]

I am trying to find a way to sum the values of payments made to date?

eg

Date Payment
01/01/2007 10
01/02/2007 12
01/03/2007 11
01/04/2007 10
01/05/2007 10
01/06/2007 23
01/07/2007 10
01/08/2007 10
01/09/2007 10
01/10/2007 10
SUM 116

So if it was today it would sum all values preceding the figure for July?

Is there an easy way to do this using a formula? I have tried using the
offset and match formula but then i can't get it to sum all previous payments.

Many thanks for your help

Jody