Error message in event table maintenance

Hi

I have a specific table for which I want to have mandatory fields filled in by my users.

The table have the following fields

Maintenance plant (data element IWERK)

Article (MATNR)

Plant (WERKS_D)

Stor loc (LGORT_D)

Maintenance plant and article are the table keys.

Transaction SM30 is used to fill in the data.

I put the following code for event 05 (new_entry).

form new_entry.

if zcs_div_mag_art-division is initial.

   message e900(sv) with zcs_div_mag_art-article.

endif.

if zcs_div_mag_art-magasin is initial.

   message e901(sv) with zcs_div_mag_art-article.

endif.

endform.

When filling the data I got the right error message, but the fields plant and storage location are grey so that I can't fill in and correct the entry.

I tried also to use the event 01 when saving but the issue is the same.

I tried with message type w, but a warning is not enough as the user can pass it.

Any idea?

Regards

Olivier