/**
	 * Encode a string according to W3C standards.
	 *
	 */
	public static String urlEncoder(String s) {
		if (s == null)
			return s;
		StringBuffer sb = new StringBuffer(s.length() * 3);
		try {
			char c;
			for (int i = 0; i < s.length(); i++) {
				c = s.charAt(i);
				if (c == '&') {
					sb.append("&amp;");
				} else if (c == ' ') {
					sb.append('+');
				} else if (
					(c >= ',' && c <= ';')
						|| (c >= 'A' && c <= 'Z')
						|| (c >= 'a' && c <= 'z')
						|| c == '_'
						|| c == '?') {
					sb.append(c);
				} else {
					sb.append('%');
					if (c > 15) { // is it a non-control char, ie. >x0F so 2 chars
						sb.append(Integer.toHexString((int)c)); // just add % and the string
					} else {
						sb.append("0" + Integer.toHexString((int)c));
						// otherwise need to add a leading 0
					}
				}
			}
 
		} catch (Exception ex) {
			return (null);
		}
		return (sb.toString());
	}