Displaying exposed filter form for views in Drupal 6
$view = views_get_view('your_view_name');
$view->set_display('default');
$view->init_handlers();
$form_state = array(
'view' => $view,
'display' => $view->display_handler->display,
'method' => 'get',
'rerender' => TRUE,
'no_redirect' => TRUE,
);
$output = drupal_build_form('views_exposed_form', $form_state);
return $output;