http://community.borland.com/article/0,1410,19650,00.html

A short summary cut from the above FAQ:

 1)  declare all of the GUI components to be instance variables 

   This ensures that the components are recognized as permanent 
   members of the class, and as such, they will be displayed in the 
   Structure pane.

 2)  wrap all of the initialization code in a jbInit method.

   When building the class representation in the UIDesigner, the 
   parser looks for a method with the signature:  private void jbInit() 
   throws Exception,and the representation is built based on the code 
   defined in this method.  Any additions or changes made to the class 
   outside of the jbInit() method will not be visible in the UIDesigner.

 3)  add call to jbInit() in the applet's now empty init() method (or 
   in an equally appropriate place, depending on your code).