arrow key control

int x, y;

void setup(){
   size(640,480);
   x = width/2;
   y = height/2;
}

void draw(){
   background(0);
   if( keyPressed == true ){
      if( keyCode == LEFT ) x--;
      else if( keyCode == RIGHT ) x++;
      else if( keyCode == UP ) y--;
      else if( keyCode == DOWN ) y++;
   }
   ellipse(x, y, 5, 5);
}