DataGrid blues...

Question

I have a DataGrid control on Windows Form bound to a MS Access data table with 12 rows of data. The user requirement is that there should only ever be 12 rows of data in the data table. How can I turn-off the ability to add rows in the DataGrid? According to VB .net Reference books this feature is controlled at the data source, but I have had no luck finding the mechanism to do this in MS Access either. Help! Also, one of my DataGrid columns contains calculated values so I changed the ReadOnly property to True for that GridColumn. It works well in that the users cannot change the data in that column but they are still able to navigate to that column in the DataGrid. Any idea on how to prevent navigation to a particular GridColumn? The last time I worked with VB was way back in 1997 with VB 4. I seem to remember that DataGrids were easier to get along with back then... there was no coding to have a ComboBox column, for example, and I believe there was an AllowAdd property. Oh well. Thanks for any suggestions, Donna