docs: public static String stripNonNumber(String string)
      {
      	if (string == null)
      		return null;
          for (int i = 0; i < string.length(); i++)
          {
              char ch = string.charAt(i);
              if (!(Character.isDigit(ch)))
                  if (ch != gchDot)
                  if (ch != gchMinus)
                  {
                      string = string.substring(0, i) + string.substring(i + 1);
                      i--;
                  }
          }
          return string;
      }