IFF function in SSIS

I want to set up a label to update dynamically..I can use either a Case Statement or an IFF, But I am not sure exactly how to do it..
For example, I have 4 employees, Mary, Tom, Pete, Gordon,,HOW do I set the IFF function, that when Mary is selected, it updates that Mary is Female, Pete is Male and so forth.
or any good Links I can follow.

Thanks in advance.

Handling this case in database is easy way. But without any clue how can identify male or female. That should be available in source itself.