c = *++z;
    if( c2>=0x80 ){
      if( ((c2<0xc2) || (c2>=0xf4) || ((c&0xc0)!=0x80)) &&
          (((c2!=0xf4) || (c>=0x90)) && ((c2!=0xc0) || (c!=0x80))) ){
        return LOOK_INVALID; /* Invalid UTF-8 */
      }
      if( c2>=0xe0 ){
        if( c2>=0xf0 ){
          if (c2==0xf0 && c<0x90) return LOOK_INVALID; /* Invalid UTF-8 */
          c = (c2<<1)|3;
        }else{
          if (c2==0xe0 && c<0xa0) return LOOK_INVALID; /* Invalid UTF-8 */
          c = (c2<<1)|3;
        }

      }else{
        c = ' ';
      }
    }
  }
  return (c>=0x80) ? LOOK_INVALID : 0; /* Last byte must be ASCII. */
}