I built a small database to test this.
Personally I don't use the not in list event because it is always too
restrictive for my needs.
The easiest way I have found for your situation is to use some formatting to
simplify things.
Assuming that tblFirstRatePostageRates has the postage field as its primary
key-->
In the table, set the format for that field to Fixed and decimal places to
2.
In the postage combo on the form, set the format to Fixed and decimal places
to 2.
To get the not in list event to work for you, you will need to type the 0
followed by the decimal point and the number.
This way you are saved the bother of typing the dollar sign.
The Not In List event works well for a table with only one field and where
that field is text and can be used with long integer.
For other situations it is easier to build your own form that will add
values to the table, and let the user double click the combo to add new
values to the list.
Jeanette Cunningham MS Access MVP -- Melbourne Victoria Australia