"Meanwhile , just need one more help on the following error :
## parent element "0.0" does not exist at /usr/lib/perl/Tk.pm line 250 ###"

Without seeing your code, I can't help you with that. You'll need to look in /usr/lib/perl/Tk.pm and see what's happening at line 250. Then try to work out how your code is calling that line.

In the current version (804.032) of Tk, the source (http://cpansearch.perl.org/src/SREZIC/Tk-804.032/Tk.pm) shows line 250 as a simple assignment (my $name = $meth;): I don't see how that would generate an error about a "parent element". You probably have a different version.