BASE/1066    Argument error: conditional

     Explanation:  This error can occur for two reasons:

     1. You specified an argument for a conditional statement such as IF or
        DO WHILE that did not return a logical value.

     2. You specified the IF() function and the first argument did not return
        a logical value.

     Action:  Correct the program.

     See Also:  "Basic Concepts" chapter in the Programming and Utilities
     Guide