r.a.d.treeview is flexible enough to accommodate a variety of client-side scenarios. In this particular example we've simulated a combo-box that displays a treeview - the treeview populates the textbox on top when the end-user selects a city from the treeview. We're also using the client-side API of r.a.d.treeview to restrict the selection only to cities - i.e. end-users will not be able to select continents and countries.