Having issues with resizing my SDL::App

[Dennis Meinen]

Hi

I'm currently working on a simple game.

But now I'm trying to resize the SDL::App windows by using the following
code

my $app = new SDL::App(
   -title=>$title,
   -width=>800,
   -height=>600,
   -depth=>32,
   -flags=>SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWACCEL,
   -resizeable,
);

$newx=640;
$newy=480;

$app->resize($newx, $newy);


But this wont work
Are there any other steps required?

Dennis