CBO box on form doesn't add data to table

[Carmen]

I have a drop down box on my form which gets the data from a query
(course). I have another text box (for distance) on my form which
uses cboCourseList.Column(1) as the source. What happens is on the
form when you choose a course it automatically enters the distance.
However, in the table it will update/add the data entered in the form
except for the distance field. What do I need to do to have the data
updated/added to the table. I am new to access.

Thanks,
Carmen