<table border=1>
<tr>
<td>up</td>
<td id="thisEL" onclick="alert(this.nextSibling.innerText)">this</td>
<td>next</td>
</tr>
</table>
<tr>
<td>up</td>
<td id="thisEL" onclick="alert(this.nextSibling.innerText)">this</td>
<td>next</td>
</tr>
</table>
<tr>
<td>up</td>
<td id="thisEL" onclick="alert(this.nextSibling.innerText);alert(this.previousSibling.innerText)">this</td>
<td>next</td>
</tr>
</table>