You can set up expressions in Manage | Security.... that limit a user to just the records their account name or privilege set allows them to see.
See "Editing record access privileges" in FileMaker Help and check out this particular sub section: "Entering a formula for limiting access on a record-by-record basis" for a detailed description of how to set this up.
Thanks a lot. for reply. it worked fine.
Thank you, PhilModJunk, This worked perfect. I wouldn't have even known where to start looking. You're a life saver!