有關增添 jQuery 效果

大家好。本人初用 drupal, 嘗試寫一些 module作測試。剛好見到 Druapl 有缺省載入 jQuery 於是跟從了以下網頁試
HOWTO: Add a jQuery effect, 但發覺好像沒有 Fadein 的效果, 那是因為我寫錯了東西嗎？以下是我的 code:

function test_menu(){
$items['test/go'] = array(
'title' => 'Test using jQuery javascript Fade-in effect',
'description' => '...',
'page callback' => 'test_jquery',
);
return $items;
}

function test_jquery() {
drupal_add_js (
'$(document).ready(function(){$("p.jtest").fadeIn(6000);}); ',
'inline');

$output = "
This is an example of an effect which is built into the core jQuery
library. This text should fade in after the DOM is loaded.
drupal_add_js() was used to add the fadeIn effect to any paragraph with the class jtest.
";

return $output;
}

我所使用的是 6.4 version, 煩著大家了, 謝謝