Combox Box that allows user to enter in a value not in the list

Combox Box that allows user to enter in a value not in the list

I want to use the combo box widget that autocompletes, but I need to be able to have the user enter in a value that is not in the list.

Is there an easy way to do this?

How do I retrieve the currently entered in value in the combo box autocomplete field?

I suppose I could use this to add a value to the combo box when the user submits the form.

I have multiple combo boxes, how would I reference each one?

Thanks for any help.