Multiple Class Change On Hover / Rollover

In the past I've done image rollovers and that's fine. I got scripts for those, and got them to switch fine. But what I want to do is edit the backgroudn color of a TD, which is code defined, and not an image. Anyways, the basic thing I'm doing is a table that hold lots of numbers. I'm creating a "times table" - which looks roughly something like this:

......1 2 3 //top row (multiples)
1.....1 2 3
2.....2 4 6
3.....3 6 9

Now, when you rollover, let's say, the '6' - the TD background color for the '6', left '2' and top '3' would change to a different color (bolded in this example). This would work the same way for every other number as well, which involves overlapping classes. I've search for an answer for hours, to no avail. And here's a more "code specific" example of the table:

Code:
<table>
<tr>
<td>1</td><td>2</td><td>3</td>
</tr>
<tr>
<td>1</td><td>1</td><td>2</td><td>3</td>
</tr>
<tr>
<td>2</td><td>2</td><td>4</td><td>6</td>
</tr>
<tr>
<td>3</td><td>3</td><td>6</td><td>9</td>
</tr>
</table>

Also, the image rollover script I have goes like this:
Code:
<script type="text/javascript">
function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
} .....