default WINDOW

Sorry, Darrel.

What I meant was G_get_default_window(window).
After I sent out the email, I realized that.
I forgot I had a copy of GRASS program manual with me here.
You know I should have brought more with me.

Oh, I try to use D_get_u_north() (also for other three).
But it won't compile for me. I recall they're GRASS funs,
aren't they?

--Xin