[AccessD] Data Type Mismatch in Criteria Expression

The following criteria generates the data type mismatch in criteria expression error. The field PID is a text field. What am I missing?

Expr1: IIf(Right([ConfigMaster].[PID],1)="S" Or Right([ConfigMaster].[PID],1)="L",
Right([ConfigMaster].[PID],Len([ConfigMaster].[PID]-4)),2)

The following works correctly

Expr1: IIf(Right([ConfigMaster].[PID],1)="S" 
Or Right([ConfigMaster].[PID],1)="L",1,2)

Chester Kaup
Engineering Technician
Kinder Morgan CO2 Company, LLP
Office (432) 688-3797
FAX (432) 688-3799

 
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