Dynamic dropdown for usernames

I've read almost every post discussing similar things but can't find exactly what I need. I'm new to Lectora.I have an Access database which contains all employees names and I have the code which generates a dropdown with all of their names. What I can't seem to get working is to set the value selected (onChange) to a variable which I can use to submit into the database after the test is completed. This dropdown only needs to appear on a page prior to the user taking the test.Any help is greatly appreciated.