Size and position of subwindows

Hi there.
I'm modifying an old API-Style program and want to compile it with the new 
OpenGL-Haskell-API.
In the past one defined a subwindow in the following way:

uniW<- createSubWindow mainW (WindowPosition space space)
	       (WindowSize 600 400)

Now the parameters are away. You define a normal window by setting the 
statevars and create one.

   initialWindowSize $= Size 100 100
   initialWindowPosition $= Position 100 100
   createWindow progName

Whats about subwindows? What have to be done if you want to create a subwindow 
at position 50,50 relatively to mainwindow with a specific size?

And how does the reshaping of subwindows work?
If you resize your mainwindow, the mainreshape is called with the new size.
When and with what size is the subwindow reshapecallback-func called by 
OpenGL? Or am I forced to call it by myself in the mainreshape?

Greetings
Patrick