Make sure the control wizzard button is depressed in the tool box. Click on
the combo box tool and then click on your form. Follow the wizzard. Then
you may have more questions.
A "drop down box in a table" is a lookup field and should be avoided.
They violate the relational rule that says that no field should
contain the result of a calculation on any other piece of data in the
database.
Do a google search on these newsgroups on Lookup Fields.