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IBM i and CPF operating system restrictions prevent logic like the following example from ever working correctly on two (or more) browse lists:

     SELECTLIST NAMED(#LIST01)
     << process LIST01 entry >>

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                SELECTLIST NAMED(#LIST02)

           << process LIST02 entry >>

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                << process LIST02 entry >>
                UPD_ENTRY  IN_LIST(#LIST02)

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                ENDSELECT
     UPD_ENTRY IN_LIST(#LIST01)

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              ENDSELECT

The reason is that all browse lists belong to the same "file" (ie: display file) and therefore the update implicitly attempts to update the last "record" processed in the "file". If a program like this example was compiled, it would fail on the UPD_ENTRY command to #LIST01 with an error indicating an update was attempted "without a prior read".

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This restriction can usually be overcome by altering the point at which the update operation is performed like this:

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   SELECTLIST NAMED(#LIST01)

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     << process LIST01 entry >>
  => UPD_ENTRY IN_LIST(#LIST01)

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                SELECTLIST NAMED(#LIST02)

              << process LIST02 entry >>

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                << process LIST02 entry >>
                UPD_ENTRY  IN_LIST(#LIST02)

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                ENDSELECT

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     ENDSELECT

If a solution like this cannot be implemented, use a GET_ENTRY command immediately before the UPD_ENTRY command.

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