http://qs321.pair.com?node_id=201500
Description:

Tk allows 'tab-key' ordering by the order in which you pack your widgets. One way to change this behaviour is to bind a key event to the focus method of the 'next' widget in line.

In this snippet, I bound the return key to the next 'Entry' widget in line. Uncomment the line noted in the code if you want to wrap around.

--
hiseldl
What time is it? It's Camel Time!

 
use Tk;
use strict;
use warnings;

my $win = MainWindow->new();
$win->Button(-text=>'Other Window',-command=>\&otherwindow)->pack;
sub otherwindow
{
    my $otherwin = $win->Toplevel;
    my $foo = $otherwin->Entry->pack;
    my $bar = $otherwin->Entry->pack;
    my $baz = $otherwin->Entry->pack;

    &defineOrder($foo, $bar, $baz);
}    

sub defineOrder
{
    my $widget;
    for (my $i=0; defined( $_[$i+1] ); $i++)
    {
        $_[$i]->bind('<Key-Return>', [\&focus, $_[$i+1]]);
    }

    # Uncomment this line if you want to wrap around
    #$_[$#_]->bind('<Key-Return>',  [\&focus, $_[0]]);

    $_[0]->focus;
}

sub focus
{
    my ($tk, $self) = @_;
    $self->focus;
}

MainLoop();