$form->addInput(array('type'=>'combobox',
'name'=>'favorite_report',
'onchange'=>'document.reportForm.fav_report_changed.value=1;document.reportForm.submit();',
$form->addInput(array('type'=>'combobox',
'name'=>'favorite_report',
'onchange'=>'document.reportForm.fav_report_changed.value=1;document.reportForm.submit();',