Cannot read top level base window

[Leonid Syrkin <lsyrkin(at)mediaone.net>]

Hi!

I am trying to add "Save As.." feature into the IDL 5.0 program.
I need to capture the whole top level base widget window for saving it
into a file. This window contains several graphics windows inside.  The
problem is that I don't know how to get window ID for this base. In the
program I do:

widget_control, event.top, tlb_get_size=result
tlb_xsize = result[0]
tlb_ysize = result[1]
widget_control, event.top, tlb_get_offset=result1
tlb_xoffs = result1[0]
tlb_yoffs = result1[1]

;Above  works fine and gives me offset and size of the base window.

 img=BytArr(tlb_xsize,tlb_ysize)

; Now trying TVRD I am getting error as it reads one of the graphics
windows inside the base window.
 img=TVRD(tlb_xoffs,1024-tlb_ysize-tlb_yoffs,tlb_xsize,tlb_ysize)


What should I add to make it read the window I need?

Thank you in advance,

Leonid Syrkin.