>ItemNo is a string. You assign null to a string like this:

ItemNo = null;

What are you trying to do? Assigning null to the string parameter or to a field of the datatable?
>
>>How can I fix this code

>public InventoryDS.ItemsDataTable Find(string ItemNo, string description)  
>>        {
>>            if (ItemNo.Equals(string.Empty))
>>            { ItemNo = DBNull.Value; } // Intellisense doesn't like it

>Both parameters set to allow DbNull.

BTW, would it allow it if it's not declared as string? It didn't complain in the code window.