As a programmer, you can take different paths to build thinBasic script user interface.
Currently, there are two most straightforward approaches:
oDesigning whole dialog from code
oDesigning whole dialog via Tools / User tools / Resource editor
Both approaches allow you to further add controls from code and process the dialog events via low level or high level interface from thinBasic script.
In order to use the high level approach, you need to have dialog pseudo-objects available.