sub drag_group {
    my ($c) = @_;
    my $e = $c->XEvent;
    # get the screen position of the move...
    my ( $sx, $sy ) = ( $e->x, $e->y,,, );
    print "\t screen: $sx, $sy\n";
    # get the canvas position...
    my ( $cx, $cy ) = ( $c->canvasx($sx), $c->canvasy($sy) );
    print "\t canvas: $cx, $cy\n";
    # get the amount to move...
    my ( $dx, $dy ) = ( $cx - $draginfo{lastx}, $cy - $draginfo{lasty} );
    print "\t dx, dy = $dx, $dy\n";
    
    # move it...
    $c->move( $draginfo{id}, $dx, $dy );
}

##</code><code>##

sub items_retrieve {
    my $id = shift;
    my @items = @{$group{$id}{items}};
    return @items;
}