replacing elements/changing attributes with 'remote_function' ?

Hi,

how could I replace more than just the innerHTML of an element with a
remote function?

The given problem:

I'd like to update table row in a table of the style

<table>
   <tr id="row1" class="good">...</tr>
   <tr id="row2" class="alert">...</tr>
   ...
</table>

where not only the contents of the tr change, but the class attribut
as well (e.g. to change the background color into red for alerting).

With the argument :update=>:row1 I could replace the innerHTML,
but not the class attribute.

How would I do this?

regards
Hadmut