I need to do something in SQL and I'm currently confused!

So I have something like this:

```
idEvent   idService   dateCreated
-------   ---------   -----------
1         1           2012-01-01
2         1           2012-02-02
3         2           2012-01-01
4         2           2012-02-02

```

The `idEvent` is auto-incrementing.

What I need to get is the biggest row (ordered by `dateCreated DESC`) for each `idService`.

So I'd need to get this as a result :

```
idEvent
-------
2
4

```