How to change table's background image?

[Dylan Leblanc]

On my page I have a table

<table style="background-image: url('grid.png')">
...
</table>

How can I make a link that will change the background image of that table?

<a href="#" onClick="document.???=solid.png">

[Mr J]

<table id="tab" background="pic1.jpg" width="200" height="200">
<tr>
<td></td>
</tr>
</table>

<P><a href="#null" onclick="tab.background='pic2.jpg'">Change pic</a>