Name Comparison Through Several Sheets

[athena53]

I have 5 sheets with employee names that need to be compared. Each sheet has different times that an employee should have received a review; raise, promotion, transfer, pay class change, and job title change. If an employee received two of these events at the same time they only need one review so I need something that tells me that the name is on one of the other sheets.
Was trying conditional formatting but that doesn't seem to be working with multiple sheets.
Thank You
Athena

 

[NeonRedSharpie]

=COUNTIF(Sheet1!$A:$A,"John")+COUNTIF(Sheet2!$A:$A,"John")+COUNTIF(Sheet3!$A:$A,"John")

Where "John" is likely to be A2.

Unfortunately COUNTIF is not a 3D function, so this is probably the easiest way to get it done quickly.