Nullability in MsAccess

Hi,
I am failing to get the nullability of a field (msaccess db with odbc classes in vc5).
I am trying this:

cstrSql = "select TOP 1 ID from MyTable";
rsData.Open(CRecordset::snapshot ,cstrSql,CRecordset::readOnly);
rsData.GetODBCFieldInfo("ID",fieldinfo);
if (fieldinfo.m_nNullability==SQL_NULLABLE)
...;
else
...;



- but I get only "SQL_NULLABLE" although I change the "Required" property of the field in MsAccess.

Any ideas?
Is there any other way (not dao classes)?
Oren.