ComboBox should be empty for new records

Hi,

already searched in the groups for an answer, but couldnt find :-(

I have an unbound combobox which looks up values (names) in a table
and creates a new record in the form with some data from this table
(Event After Update).

Problem:
The comboBox shows the last selected row. I want the combobox always
to be empty when the user creates a new record.
Otherwise the user might think that the name in the box is already
selected and the AfterUpdate Procedure wont be executed.

Maybe there is an easy (vba) solution, but unfortunately I couldnt
find it.

Thanks for your help!

Andreas