export jpeg frustration

[Chris Carroll-Davis]

Hello folks.

Can anyone shed any light on this?  I'm having problems with the export 
syntax.  I am trying to export an area of a window...

The snippet below works fine, happily creating a jpeg in the default 
folder, but using screen coords (which I don't want)

        put the ticks & "temp.jpg" into tFile
        put the rect of graphic "PFrame" into pRect
        put the id of this wd into WinId

        put prect && winId && defaultfolder && tFile

        export snapshot from rect pRect to file tFile as JPEG



But if (as below) I add the window parameter to use window-relative 
coords, it doesn't work.  Instead, I get the error:  "export: no image 
selected, or image not open".  It's as if it is suddenly ignoring the 
"snapshot" form of export.

        put the ticks & "temp.jpg" into tFile
        put the rect of graphic "PFrame" into pRect
        put the id of this wd into WinId

        put prect && winId && defaultfolder && tFile

        export snapshot from rect pRect of window WinId to file tFile as 
JPEG


BTW, in my case, the message box returns:

240,480,960,960 1076 /Volumes/Starfish Internal 250/Scripter/lessons 
66803362548temp.jpg

so the variables are evaluating ok I think.

Help!!!

Tearing my hair out (what's left of it) with this one.

Chris