dbgrid behaviour

My problem

How (tabel, datasource, dbgrid) can I prevent the user editing the value in a particular cell, depending on the value in an other cell?
I tried it in the following way.

Tabel has two fields: CN and CNFLAG. If CNFLAG = TRUE changing the value of CN must be impossible. Therefore I tried to create an exception in the Onvalidate handler of CN.
if TABLECNFLAG.value then begin
                            exception.create('XXXXX');
                            abort;
                          end;
This brings up the message XXXXX but after that the user has to press the escapekey to redisplay the original value of CN. Is there an easy way to circumvent this problem?
ahjkuipersAsked:
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Pegasus100397Commented:
Try this:

In the Datasource's Datachange event:

With Datasource1.Dataset DO
   Begin
     if FieldByName('CNFLAG').AsBoolean = TRUE then
        Begin
         FieldByName('CN').ReadOnly := True;
         Showmessage('Edits NOT allowed')
       end
else
    FieldByName('CN').ReadOnly := False;
   end;

Your datasource & fieldnames may be different.

Good luck with your project!
Pegasus
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ahjkuipersAuthor Commented:
Thank you!
0
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