Hi Jeff and Thanks Al,
Sorry - I was away on holidays and repleid off the top of my head - I am now back home and checked my code, an example below -
tblCustomers.cusRsnID..Null=True
I found I had to use this when working with MSSQL tables rather than using tblCustomers.cusRsnID=NULL
otherwise it would not work when trying to write to the MSSQL table - I guess therefore that using Hyperfile SQL would be much the same.
Milton