#!/usr/bin/perl
use Tk;
$mw = tkinit;
$mw->bind("<Return>" => sub { warn "Old binding" });
my $old_binding = $mw->bind("<Return>");
$mw->bind("<Return>" => sub { $old_binding->Call();
                              warn "New binding" });
MainLoop;
__END__

##</code><code>##

#!/usr/bin/perl
use Tk;
$mw = tkinit;
$mw->bind("<Return>" => sub { warn "Old binding" });
$mw->bind("anotherbindtag", "<Return>" => sub { warn "New binding" });
$mw->bindtags(["anotherbindtag", $mw->bindtags]);
MainLoop;
__END__