public Paddle(int xInitial, int yInitial) throws IllegalArgumentException{
		
		// Check to see if the x-axis position is within bounds.
		if (xInitial >= PADDLE_MIN_X && xInitial <= PADDLE_MAX_X) {
			xPosition = xInitial;
		} else {
			throw new IllegalArgumentException("Initial horizontal position out of bounds.");
		}
		
		// Check to see if the y-axis position is acceptable.
		if (yInitial == PADDLE_LOWER_Y || yInitial == PADDLE_UPPER_Y) {
			yPosition = yInitial;
		} else {
			throw new IllegalArgumentException("Initial vertical position out of bounds.");
		}
	}