Tk::Error: Can't call method "configure" on an undefined value at dispatch.pl li
ne 158.
 [\&main::__ANON__]
 Tk callback for .frame.button
 Tk::__ANON__ at C:/Perl/site/lib/Tk.pm line 228
 Tk::Button::butUp at C:/Perl/site/lib/Tk/Button.pm line 111
 (command bound to event)