How to programmatically associate a flash .fla file with a document class?

I heard about jsfl (Flash IDE API) so I gu开发者_StackOverflow社区ess it is possible but I can't find any concrete example ?

var myDocument = fl.getDocumentDOM();  
// set the property  
myDocument.docClass = "com.mycompany.ManagerClass";  
// get the property  
fl.outputPanel.trace("document.docClass has been set to " + myDocument.docClass);

ref: http://help.adobe.com/ru_RU/Flash/10.0_ExtendingFlash/WS5b3ccc516d4fbf351e63e3d118a9024f3f-7fd0.html