[R-gui] tutorial on gwidgets?

[Antje]

Hello everybody,

is there any nice tutorial how to use gwidgets? Of course, I've found how to 
create simple elements like buttons, but I could not figure out for example how 
to create a window with a special size and a gtree on the left side (taking the 
whole height of the window) and some other elements on the right side...o 
especially I'm looking for information about layout design possibilities... (or 
limitations)

Antje