This event is triggered whenever the user selects a token.
As a frame-based event, a frame containing the event code has to be opened.
Create a frame that has this special html tag in it:
<link rel='onChangeSelection' type='macro' href='macroLink'>
macroLink by an actual macroLinkText-call to a macro of your choice (the returned value of macroLinkText()). A common practice is to call the frame opening macro itself to actualize the content.