# Create a TK object hash
  our %TK;

  # Generate a key
  $NVP{'Id'}=&newkey({'Join'=>''});
   

  # Create the popupwindow
  $TK{'pw-'.$NVP{'Id'}}=$TK{'mw'}->Toplevel('-title' => $NVP{'Title'});

...

  # Create the main canvas
  $TK{'canvas-'.$NVP{'Id'}}=$TK{'pw-'.$NVP{'Id'}}->Canvas(-background => $NVP{'Background'},
                                                          -bd         => 1,
                                                          -relief     => 'sunken')->pack(-fill   => 'both',
                                                                                         -anchor => 'center',
                                                                                         -expand => 1);

...

  # Create an image
  $TK{'image-'.$NVP{'Id'}}=$TK{'canvas-'.$NVP{'Id'}}->Photo($imagename,
                                                            -file   => $NVP{'File'},
                                                            -format => $extension);