public void keyReleased(KeyEvent e) {
        int key = e.getKeyCode();
        if (key== KeyEvent.VK_SPACE) {

        }

        if (key == KeyEvent.VK_LEFT) {
            dx = 0;
        }

        if (key == KeyEvent.VK_RIGHT) {
            dx = 0;
        }

        if (key == KeyEvent.VK_UP) {
            dy = 0;
        }
        if ((key==KeyEvent.VK_ESCAPE) || (key==KeyEvent.VK_N))
        {
            //Collision c=new Collision();
            System.exit(n);
        }       
        if (key == KeyEvent.VK_DOWN) {
            dy = 0;
        }
        if ((key==KeyEvent.VK_P)) {

        }

    }