How to determine the number of rows returned from a Filter instruction in vb 2010

Using a SQL Server 2008 Express database and VB 2010 Express.

I am using the following instruction to search for a duplicate record.

ManagersTableBindingSource.Filter = ("MgrLN" = PubMgrLastName And "MgrFN" = PubMgrFirstName)

How can I determine if any records were returned??