hello guys, i have a function with xajax working that modify a div, is this:

include 'includes/xajax/xajax_core/xajax.inc.php';

$xajax = new xajax();

$rqstAdd =& $xajax->register(XAJAX_FUNCTION, 'post_wall');

function post_wall()
{
    // Instantiate the xajaxResponse object
    $objResponse = new xajaxResponse();
   
   
    $objResponse->assign("mensaje123456","innerHTML", "hello world");
   
    //return the  xajaxResponse object
    return $objResponse;
}

$xajax->processRequest();

?>

but when i instance inside a object( p=new Person(), for example) and i call his methods xajax doesn't work.
isn't there support for php objects in xajax or i have to do something more or whats happen?? please help!