Extract duplicated values based on an extra criteria

Hi,

I'm trying to get a formula in column "Valid" to get "Yes" value for the latest registered names according to "Date" column (see the example below).

Thanks for any suggestion,
Eduard

Date	Name	Valid
01/03/2013	AAA
15/03/2013	BBB	Yes
18/03/2013	CCC	Yes
06/03/2013	AAA
06/03/2013	BBB
31/03/2013	AAA	Yes