Dropdown menu and OnFocus events

Hi

I'm designing Drop-down menus (client insists!) and we're making sure that 
the top button (the one that mouseover/onFocus will cause the dropdown to 
dropdown) will go to an intermediate page in case of browser 
incompatability / JS not enabled etc. We'll also use the [Alt] accesskeys 
for these.

The table cell which contains the drop-down table has an onMouseover which 
ensures that the dropdown stays displayed if mouse is over it.

Bobby advises that there should be an OnFocus event handler too - for those 
without mice. So I added one.

Now the page fails the W3.org validator for 4.01 Transitional because 
onFocus isn't allowed in a <td>.

The only way out of this that I can think of is to use an image in each of 
the cells of the dropdowns and have them enclosed by <a>...</a> (onFocus IS 
allowed in <a>...</a>).

But I don't really want to have images - text is quite adequate...

Thanks


David