==================== error message =========
 error:not a Tk object
 Tk::die_with_trace at destroyWinExpert.pl line 22
 main::__ANON__ at c:/programs/Perl/lib/Tk/Widget.pm line 363
 (eval) at c:/programs/Perl/lib/Tk/Widget.pm line 363
 (eval) at c:/programs/Perl/lib/Tk/Widget.pm line 363
 Tk::Widget::_Destroyed at c:/programs/Perl/lib/Tk.pm line 411
 (eval) at c:/programs/Perl/lib/Tk.pm line 411
 Tk::MainLoop at destroyWinExpert.pl line 13
=======