R help - Aug 2006 - tktoplevel & tkgetSaveFile options

Dear list, 

Previously I posted these question to R-SIG-GUI. Perhaps here is a better place.

1. Is there some option for mantaining the tktoplevel window always on top?
2. Is there some option to eliminate the border icons maximize, minimize and
close of a tktoplevel window?
3. Is possible to avoid the warning message (or changing its contents) in
tkgetSaveFile when the file to save already exists?

Thanks,

Manel