Causes DEC DATATRIEVE to execute one of a series of statements
       or compound statements, depending on the evaluation of a series
       of conditional (Boolean) expressions. The CHOICE statement is a
       convenient substitute for nested IF-THEN-ELSE statements.

       Format

         CHOICE  [OF]

              boolean-expression-1 [THEN] statement-1
              [boolean-expression-2 [THEN] statement-2]
                         .         .      .
                         .         .      .
                         .         .      .
              [ELSE statement-n]

         END_CHOICE