public void move()
   {
//     if(x<=10)
//       xdir = 1;
//     else if(x>=BALL_RIGHT- 10)
//       xdir = -1;
//     if(y<=10)
//       ydir=1;
//     else if(y>=BALL_DOWN- 10)
//       ydir=-1;
     if (xdir == 0)
       y += speed * ydir * 1.3;
     else
       y += speed * ydir;
     if (ydir == 0)
       x += speed * xdir * 1.3;
     else
       x += speed * xdir;
   }