Table maintenance generator events 05

Hi all,

Can anyone help me how to write the below logic in event 05 with forms

Table name : YSTEST

How to  implement the following checks in the maintenance dialog at input time. In case of error display the message E398(00) with the given text:

Fields :

1. Field aaa1: not initial, Error message: “Bitte Bezugszeitraum eingeben”
2. Field bbb2: not initial, numeric, Error message: “Bitte Company eingeben”
3. Field cccc3: not initial, Error message: “Bitte Kartenorganisation eingeben”
4. 4. Field dddd4: not initial, Error message: “Bitte Positionsnummer eingeben”
5. 5. Field eee5: not initial, Error message: “Bitte BIN eingeben”
6. 6. Field ffff6: not initial, Error message: “Bitte Verteilungskriterium eingeben”
7. 7. If field ffff6 = M, then field gggg7 must be initial. Error message: “Verteil.Betrag nur bei manueller Verteilung möglich”
8. If field gggg7is not initial, then at last one of the fields PBlacK1 – PBlacK30 must contain a value and the fields FGPB1 – FGPB30 must be initial. Error Message: “Mindestens eine Principal Bank vorgeben”
9. If field gggg7 is initial, then at last one of the fields PBlacK1– PBlacK30 and the corresponding field FGPB1 – FGPB30  must contain a value. Error Message: “Betrag fehlt bei Pblack”

regards,

vikas