<table><tr>
<td>
<a href="image1.gif" onclick="return changeImg(this.href);">Image 1</a><br />
<a href="image2.gif" onclick="return changeImg(this.href);">Image 2</a><br />
<a href="image3.gif" onclick="return changeImg(this.href);">Image 3</a><br />
</td>
<td>
<img src="default.gif" name="mainImg" id="mainImg" />
</td>
</tr></table>