>Here's the whole expression:
>

>"=HA(N" + ALLTRIM(STR(RECNO()+1))+ "=SZUM(Y" +ALLTRIM(STR(RECNO()+1))+;
> ":AE"+ ALLTRIM(STR(RECNO()+1))+ ");"+'"'+"OK"+'"'+";"+'"'+"Nem OK"+'"'+")"
>

>
>It gives the result of this:
>

>=HA(N1=SZUM(Y1:AE1);"OK";"NemOK"), 
>

>
>But I get the error...

Are you sure the final comma is required?

I see that you can now write "OK". Seventeen years ago I had a "hiba uzenet", with some text describing the error and an OK button. The doctors at the rendelőintézet were confused. They thought that "OK" meant "az ok" (the cause) and were surprised when the message window just vanished when they clicked. I had to change it to "O.K.".