获取文件名并即时显示出来的

 <div id="main">
    <!--表格-->
    <form action="Media!media_yy_add_do" method="POST" enctype="multipart/form-data">
      <table width="580" border="1" bordercolor="#FFFFFF" class="md_tb1">
        <input type="hidden" name="media.albumId" value="<Property value="playList.id"/>"/>//使用隐含的数据分析
        <tr height="30" bgcolor="#F1F1F1">
          <td width="128" class="tb11">名称</td>
          <td class="tb12"><input type="text" name="media.name"required="required">
            <span id="note-devicename">&nbsp;</span></td>
        </tr>
        <tr height="30" bgcolor="#F1F1F1">
          <td width="128" class="tb11">音乐文件</td>
          <td class="tb12"><input type="file" name="mp3"required="required" onchange="file_upload()">
            <span id="note-devicename">&nbsp;</span></td>
        </tr>
        <tr height="30" bgcolor="#F1F1F1">
          <td width="128" class="tb11">歌词文件</td>
          <td class="tb12"><input type="file" name="lrc">
            <span id="note-devicename">&nbsp;</span></td>
        </tr>
      </table>
      <div class="an1" onclick="window.history.go(-1)">返回</div>
      <input class="an1" type="submit" value="添加">
    </form>
    <script>
        function file_upload(){
            var mp3=document.getElementsByName("mp3").item(0).value;
            document.getElementsByName("media.name").item(0).value=mp3;
        }
    </script>
  </div>
</div>