I have posted this on every forum I can find, and so far, no one can figure it out!

I have an update page that pulls data for a drop-down list from a table (tbl1) for the selection values, but the main page's data come from a larger table (tbl2), also including this field. When I set the inital value of this ddlist to the field value in the larger table (tbl2), I get the following error:

Microsoft VB Runtime Error '800e005a' Invald use of Null

I know this is because I have null values for this field in some records in the larger table (tbl2). This is an optional field, but I still need the update page to display the value (in tbl2) if there is one, and I'd like to give them a drop-down for choosing an update value (from tbl1) so there are no typos (it's a 30 item list of codes). I can't set a default value for the field in the database (Access 2K), because this table is re-created by an import daily. I am running IIS 5. What can I do to make this work?

Thanks