change two select lists when one other changes

I have three select lists on my form. Is it possible to change the list on two of them when one changes ? Right now I can change only one of them.

If I attach this to one of my select lists it changes the second one.

'#ahah_bindings' => array(
array (
'event' => 'change',
'wrapper' => 'select2',
'path' => 'updateselect2',
)
)

I tried adding two bindings to the select list but only the last one worked.

'#ahah_bindings' => array(
array (
'event' => 'change',
'wrapper' => 'select2',
'path' => 'updateselect2',
),
array (
'event' => 'change',
'wrapper' => 'select3',
'path' => 'updateselect3',
)
)

Thanks