$mw->geometry('100x100-0-0');

##</code><code>##

sub CenterWindow
{
    my($window, $width, $height) = @_;
    $window->idletasks;
    $width  = $window->reqwidth  unless $width;
    $height = $window->reqheight unless $height;
    my $x = int(($window->screenwidth  / 2) - ($width  / 2));
    my $y = int(($window->screenheight / 2) - ($height / 2));
    $window->geometry($width . "x" . $height . "+" . $x . "+" .$y);
}