Can you share your DLookup so we can see the syntax.

Thanks for your reply.  I just uploaded an image file.

You can't use DLookup in the Table like that. Create a form and put the DLookup in the Default Value property of the form field.

Thank you I'll try that tonight.  I do my Access from my home office computer.

Thanks again.  Knowing what doesn't work is a good start.  I still have not been able to get my DefaultCategoryID number into the default value of that field, where it will work.  (a simple 1 to 99 number)

I'm building an Inventory database.  In our language each project is called a panel.  
Each panel has a list of items needed to build the panel.  I have a table with a list of all items that could be used .  (InventoryItemsT)  
Each record in this table has a field CategoryID  which is the key field in my CategoryT

I have a table (PanelItemsNeededT) where each record in this table has field for the ID of each possible Item as well as a field with ID of each Panel and another field with the ID of each Category of Items.  (Inventory Items are grouped into Categories so searching in combo boxes have only reasonable number of  possibilities.

A clerk will enter items for a new panel from a Form (never a table).  By having a default value for the CategoryID field (and PanelID field as well) makes data entry much easier and more secure.  
When a clerk enters new record it will automatically have the CategoryID and PanelID entered so the clerk only has to select the inventory item.

Each panel has many items with the same CategoryID number.  So this will make it much quicker  and insure no mistaken entries.

Can you point me in the right direct to be able to  enter the default values without the clerk getting into the tables?  
Or is there some other way to accomplish this??

Thank you so much for your time and efforts here.