Exception operation
The EXCEPTION operation causes the expression to terminate and to continue with the next ON_ERROR block available in the calling hierarchy. When an error block has been defined the function continues with the ON_ERROR block. Otherwise it continues with on the ON_ERROR block of the next higher expression in the calling hierarchy.
You may pass an exception code to the EXCEPTION operation, which can be retrieved from the global variable _LastExceptionCode.
Definition:
exception_op := _exception [operand] ';'