How to do a SUM with condition?

Hi,

I need make a sum with condition. I like to sum the values by month and year, for example.

Basic I need something like the function SUM-IF the excel.

| year | month | status | values |
| 2012 | 1     | 1      | 100    |
| 2012 | 1     | 1      | 50     |
| 2012 | 1     | 2      | 100    |
| 2012 | 1     | 2      | 200    |
| 2012 | 2     | 2      | 300    |
| 2012 | 3     | 2      | 50     |
| 2012 | 8     | 2      | 20     |
| 2012 | 8     | 3      | 50     |
| 2012 | 5     | 3      | 100    |
| 2012 | 5     | 3      | 20     |