form으로 값을 전달할 때, 한글을 Unicode로 넘기는 방법이 없을까요?

<form action="./encode.php" method="post" enctype="multipart/form-data" name="form_index" id="form_index">  <ul>    <li style="list-style: none">      <textarea name="message" id="message" cols="98%" rows="18">      붙여넣기      </textarea>    </li>    <h2 class="lmt">선택옵션：</h2>    <li><em>카릭터셋</em>&nbsp;&nbsp;&nbsp;        <input type="radio" name="lang" id="lang1" value="gbk" checked="checked" /> <label for="lang1">GBK</label> &nbsp;&nbsp;&nbsp;        <input type="radio" name="lang" id="lang2" value="big5" onclick="" /> <label for="lang2">BIG5</label> &nbsp;&nbsp;&nbsp;        <input type="radio" name="lang" id="lang3" value="gb2312" onclick="" /> <label for="lang3">GB2312</label> &nbsp;&nbsp;&nbsp;        <input type="radio" name="lang" id="lang4" value="euckr" onclick="" /> <label for="lang4">EUCKR</label> &nbsp;&nbsp;&nbsp;        <input type="radio" name="lang" id="lang5" value="utf-8" /> <label for="lang5">UTF8</label>    </li>    <li><em>언어설정</em>&nbsp;&nbsp;&nbsp;        <input type="radio" name="charset" id="charset1" value="0" checked="checked" /> <label for="charset1">간체</label> &nbsp;&nbsp;&nbsp;        <input type="radio" name="charset" id="charset2" value="1" /> <label for="charset2">번체</label>    </li>    <li class="msub">        <input type="hidden" name="formsign" value="<?php echo random_str(100);?>" />        <input name="encode" type="submit" value="인코딩" />    </li>  </ul></form>