help with highlight table cell script, how to add id=ignore on <th>?

[bobo420]

Highlight Table Cells Script
http://www.dynamicdrive.com/dynamicindex11/highlighttable.htm

greeting to you all!
I'm using the highlight table cell script, but when I try to put it on <th> tag it changes all the colors onMouseover to 'highligh' color, the background, table background, tr and td backgrounds... i guess I should put <th> somewhere to because script works only on tr and td?

I want to add ignore on <th> so it doesn't change on mouseover
I have a table like this
<table>
<tr>
<th><th><th>
</tr>
<tr>
<td></td><td></td><td></td>
</tr>
...
...
...
</table>

thx