[development] one AHAH action, two modified elements

Hi, I was wondering whether any of you has managed to do this: I have an ahah-enabled button in a form and two other independent elements. I wish to be able to change both of these independent elements by pressing the button, i.e. in a single ahah action. Passing an array of elements to drupal_render partly does the trick but the binding only takes place for the wrapper of the current element, with the other one not being changed. Any ideas? Thanks Thanasis