public static void move(Point p, int i){
		switch (i) {
		case 0:         		//up
			p.y++;
			break;	
		case 1:              	//down
			p.y--;	
			break;
		case 2:					//right
			p.x++;
			break;	
		case 3:					//left
			p.x--;
			break;
		default:
			break;
		}
	}