Creating Mobile Games in NetBeans

Nice tutorial to follow in 10 minutes;

Video
http://www.netbeans.tv/screencasts/Creating-Mobile-Games-in-NetBeans-441/

pdf
http://developers.sun.com/events/techdays/downloads/pdfs/6400_MobileGame_labdoc.pdf

but one exception,
need to change getMazeCanvas() on GameMIDlet.java as following

mazeCanvas = new MazeCanvas(this);

Otherwise it will give following null pointer exception

java.lang.NullPointerException
at javax.microedition.midlet.MIDletStateMapImpl.getStateImpl(+1)
at com.sun.midp.midlet.MIDletStateMap.getState(MIDletStateMap.java:46)
at javax.microedition.lcdui.Display.getDisplay(+10)
at org.netbeans.j1.game.MazeCanvas.(MazeCanvas.java:183)
at org.netbeans.j1.game.GameMIDlet.getMazeCanvas(GameMIDlet.java:640)
at org.netbeans.j1.game.GameMIDlet.svgMainMenuAction(GameMIDlet.java:255)
at org.netbeans.j1.game.GameMIDlet.commandAction(GameMIDlet.java:185)
at ..........................