use warnings;
use strict;

use Tk;
my $mw = tkinit;
my $n = $mw->NoteBook()->pack;
for(qw/foo bar baz/){$n->add($_,
                             -label => $_,
                         );}
$n->bind('<3>',[\&process_bt3,Ev('x'),Ev('y')]);
MainLoop;

sub process_bt3{
    my ($w, $x, $y) =  @_;
    my $selected = $w->identify($x,$y);
    print "selected Tab: $selected\n" if( $selected );
}