在IE和FireFox下，JavaScript需小心

<table border="1" cellspacing="0" cellpadding="0" bordercolor="red">
?? <tbody id="tbody1">
???? <tr>
??? ?? <td width="50">ID</td>
??? ?? <td width="200">Name</td>
??? </tr>
?? </tbody>
</table>
<br/><br/>
<input type="button" value="add" onClick="javascript:addSelect();"/>
<input type="button" value="delete" onClick="javascript:deleteSelect();"/>
<select id="select1">
<option value="1">aaaa</option>
<option value="2">bbbb</option>
<option value="3">cccc</option>
<option value="4">dddd</option>
</select>
</BODY>
</HTML>