Thank you, it is working!

can I ask one more question please,
now how can I extract or advance filter only the last visit based on the visit ID and other columns in the sheet, for example:

Visitor_ID....Visit_Date...........Visit_number....Data
1................July 1/2013.........1....................Red
1................July 3/2013.........2....................Blue
1................Aug 2/2013.........3....................Orange
2................july 10/2013........1....................Red
2................July 15/2013........2....................Pink

To:
Visitor_ID....Visit_Date...........Visit_number....Data
1................Aug 2/2013.........3....................Orange
2................July 15/2013........2....................Pink

Thanks again,
Amanco