求助上传文件时问题！table中每一行都可以上传，如何实现？如何修改下面的代码

  <tr>
    <td><table width="100%" border="0" cellpadding="0" cellspacing="1" bgcolor="#a8c7ce">
      <tr>
        <td width="4%" height="20" bgcolor="d3eaef" class="STYLE10"><div align="center">
          <input type="checkbox" name="test" id="checkbox" onClick="if(this.checked==true) { checkAll('test'); } else { clearAll('test'); }" />
        </div></td>
        <td width="10%" height="20" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">任务ID</span></div></td>
        <td width="10%" height="20" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">任务名称</span></div></td>
        <td width="25%" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">上传文件</span></div></td>
        <td width="*" height="20" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">任务描述</span></div></td>
        <td width="10%" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">工作量</span></div></td>
        <td width="10%" height="20" bgcolor="d3eaef" class="STYLE6"><div align="center"><span class="STYLE10">任务申请</span></div></td>
      </tr>
      <% for(StudyTask s: studyTasks){
String content = (s.getContent()==null)?"无":s.getContent();
//String detail = "<a  target='_blank' href='dosth/detailServlet?client_id="+s.getId()+"'>查看详细</a>";
//String oper = "<a  target='_blank' href='addFeedback.jsp?client_id="+s.getId()+"'>回访</a>";
String apply = "<a  target='_blank' href='ApplyServlet?studyId="+s.getId()+"'>申请</a>";
//oper +="&nbsp;  <a  onClick='return checkDel()' href='dosth/searchServlet?logic=Client&forward=listClient&operation=del&client_id="+s.getId()+"'>删除</a>";
  %>
      <tr>
       <form method="post", enctype="multipart/form-data">
       <table width="100%" border="0" cellpadding="0" cellspacing="1" bgcolor="#a8c7ce">
       <tr>
        <td height="20" bgcolor="#FFFFFF"><div align="center">
          <input type="checkbox" name="test" id="checkbox2" />
        </div></td>
        <td height="20" bgcolor="#FFFFFF" class="STYLE6"><div align="center"><span class="STYLE19"><%=s.getId()%></span></div></td>
        <td height="20" bgcolor="#FFFFFF" class="STYLE19"><div align="center"><%=s.getName() %></div></td>
        <td bgcolor="#FFFFFF" class="STYLE6"><div align="center"> <span class="STYLE19">
          <input type="file" class="file" >
          </span></div></td>
        <td height="20" bgcolor="#FFFFFF" class="STYLE19"><div align="center"><%=content %></div></td>
        <td height="20" bgcolor="#FFFFFF" class="STYLE19"><div align="center"><%=s.getCredit() %></div></td>
        <td height="20" bgcolor="#FFFFFF" class="STYLE19"><div align="center"><%=apply %></div></td>
    </tr>    
        </table>
        </form>
      </tr>
<% }%>
    </table></td>
  </tr>