Can not able to call my canvas object to my midlet in j2me?

Question

I made a form to accept the player name then On ok press it will give me an alert and on done click it will take me to a list Start,Credit and Highscore . Please help I am totally new in this field

this is start function where i made my canvas midlet

public void startGame() throws Exception
    {
        try{
             disp = Display.getDisplay(this);
        ExampleGameCanvas game=new ExampleGameCanvas();
     game.start();
       // game.addCommand(back);
      //  game.addCommand(exit);

        game.setCommandListener(this);


        disp.setCurrent(game);
    } catch(Exception ex) {

    }

this the commandAction code where I called my start() function

String lbl=c.getLabel();
            if(lbl.equals("OK")&& d==form)
            {
                 printText= new Alert("Welcome! To Road Fighter Game ! :) ",txt.getString(), null , null);
                 printText.setTimeout(Alert.FOREVER);
                    printText.addCommand(ok);
                    printText.setCommandListener(this);
                 disp.setCurrent(printText);

            }else if(lbl.equals("OK") && d==printText)
            {
                menu();
                gameMenu.addCommand(ok);
          gameMenu.addCommand(exit);
          gameMenu.setCommandListener(this);
         // int in=gameMenu.getSelectedIndex();

            }else if(lbl.equals("EXIT"))
            {
                destroyApp(true);
            }else if(lbl.equals("BACK"))
            {
                menu();
                 gameMenu.addCommand(ok);
          gameMenu.addCommand(exit);
          gameMenu.setCommandListener(this);
            }else
            {
                try {            
                    List down = (List)disp.getCurrent();
                    switch(down.getSelectedIndex()) {

                        case 0:

                            startGame();

                            break;
                        case 1: Credits();break;

                    }  
                } catch (Exception ex) {




            }


        }