How to set value for multiple select options in Zend_Form_Element_Multiselect

We can do that using the setValue function by passig array of selected values
Ex:
    $users = new Zend_Form_Element_Multiselect("users");
    $users->setLabel("Users");
    $users->addMultiOptions(array('1'=>'John Smith','2'=>'Aaron Brown','3'=>'David Beckham');
    $users->setValue(array(1,2));
    so the names John and Aaron will be shown as selected.