表格操作

<table width="100%" id="otab" border="1px" cellpadding="0" cellspacing="0">
 <thead>
      <tr>
        <th>编号</th>
        <th>姓名</th>
        <th>性别</th>
        <th>操作</th>
      </tr>
 </thead>
 <tbody>
          <tr>
              <td>1</td>
              <td>张三</td>
              <td>男</td>
              <td><a href="#">删除</a></td>
          </tr>
 </tbody>
</table>          

    <script>
            window.onload= function () {
                var otab=document.getElementById('otab');
                alert(otab.tBodies[0].rows[0].cells[2].innerHTML);
                alert(otab.tHead.rows[0].cells[0].innerHTML);
            };
    </script>