how to populates onchage event dynamically

[bilkees]

i want to basically to populate an onchange event from the database.i have 6 fields inside the database. the course name, course code, course unit, course lecturer, year and the semester. if i click on the dropdown it will populate automatically.

[Dormilich]

you can’t populate an event. events are part of the underlying system (i.e. the JavaScript engine (e.g. V8 or JagerMonkey)).

what you (probably) mean is a so-called "combo box", which uses the change event to populate the next dropdown.