W3School TIY
编辑您的代码：
<html> <head> <script type="text/javascript"> function leftAlign() { document.getElementById('header').align="left"; } </script> </head> <body> <table width="100%" border="1"> <tr id="header"> <th>名</th> <th>姓</th> </tr> <tr> <td>John</td> <td>Adams</td> </tr> </table> <br /> <input type="button" onclick="leftAlign()" value="左对齐表格行" /> </body> </html>
查看结果: