code:     protected static final boolean isAlpha(String value) {
          for (int i = 0; i < value.length(); i++) {
              char c = value.charAt(i);
              if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))) {
                  return false;
              }
          }
          return true;
      }
  
  