>Hi everybody,
>
>I have two grids on the form. The main table BldMstr sets relation into Lender table

set rela to left(lname,1) into lender

>
>If LName is NULL, I have the error, and my relation doesn't work anymore. What should I do?

I guess you van use NVL function to convert null

set rela to left(NVL(lname, "?"),1) into lender

assuming that you dont have lender names beginning with "?"