public static void drawCenter(int x0 , int y0 , int radius , byte data[]) {
		int pos;
		if (((y0 - radius) >= 0)&&((x0 - radius) >= 0) &&
		  ((y0 + radius) < 240 )&&((x0 + radius) < 960)) {
			for (int y = y0 - radius ; y <= y0 + radius ; y++) {
				for (int x = x0 - radius ; x <= x0 + radius ; x++) {
					if ((Math.pow(x-x0, 2)+Math.pow(y-y0, 2)) <= Math.pow(radius,2)) {
						pos=(240 - y)*960 + (x*3);
						if ((pos >= 0) &&(pos+2 < data.length)) {
							data[pos] = ccBlue;
							pos++;
							data[pos] = ccGreen;
							pos++;
							data[pos] = ccRed;
						}
					}
				}
			}
		}
	}