drupal_add_js 异步加载 js 有大用 有大大用

见  drupal_add_js  的定义  ( \includes\common.inc 这个文件里面)

/**
 * Add a JavaScript file, setting or inline code to the page.
 *
 * The behavior of this function depends on the parameters it is called with.
 * Generally, it handles the addition of JavaScript to the page, either as
 * reference to an existing file or as inline code. The following actions can be
 * performed using this function:
 *
 * - Add a file ('core', 'module' and 'theme'):
 *   Adds a reference to a JavaScript file to the page. JavaScript files
 *   are placed in a certain order, from 'core' first, to 'module' and finally
 *   'theme' so that files, that are added later, can override previously added
 *   files with ease.
 *
 * - Add inline JavaScript code ('inline'):
 *   Executes a piece of JavaScript code on the current page by placing the code
 *   directly in the page. This can, for example, be useful to tell the user that
 *   a new message arrived, by opening a pop up, alert box etc.
 *
 * - Add settings ('setting'):
 *   Adds a setting to Drupal's global storage of JavaScript settings. Per-page
 *   settings are required by some modules to function properly. The settings
 *   will be accessible at Drupal.settings.
 *
 * @param $data
 *   (optional) If given, the value depends on the $type parameter:
 *   - 'core', 'module' or 'theme': Path to the file relative to base_path().
 *   - 'inline': The JavaScript code that should be placed in the given scope.
 *   - 'setting': An array with configuration options as associative array. The
 *       array is directly placed in Drupal.settings. You might want to wrap your
 *       actual configuration settings in another variable to prevent the pollution
 *       of the Drupal.settings namespace.
 * @param $type
 *   (optional) The type of JavaScript that should be added to the page. Allowed
 *   values are 'core', 'module', 'theme', 'inline' and 'setting'. You
 *   can, however, specify any value. It is treated as a reference to a JavaScript
 *   file. Defaults to 'module'.
 * @param $scope
 *   (optional) The location in which you want to place the script. Possible
 *   values are 'header' and 'footer' by default. If your theme implements
 *   different locations, however, you can also use these.
 * @param $defer
 *   (optional) If set to TRUE, the defer attribute is set on the <script> tag.
 *   Defaults to FALSE. This parameter is not used with $type == 'setting'.
 * @param $cache
 *   (optional) If set to FALSE, the JavaScript file is loaded anew on every page
 *   call, that means, it is not cached. Defaults to TRUE. Used only when $type
 *   references a JavaScript file.
 * @param $preprocess
 *   (optional) Should this JS file be aggregated if this
 *   feature has been turned on under the performance section?
 * @return
 *   If the first parameter is NULL, the JavaScript array that has been built so
 *   far for $scope is returned. If the first three parameters are NULL,
 *   an array with all scopes is returned.
 */
function drupal_add_js($data = NULL, $type = 'module', $scope = 'header', $defer = FALSE, $cache = TRUE, $preprocess = TRUE) {

本人的用法  自己亲自做的  有大用

if($arg0=='listkefu'){
   drupal_add_js(drupal_get_path('theme', 'myminnellizhutwo') . '/js/listkefu/ajax_xgz_and_yywgz_num.js','theme','header',true);
   $vars['scripts'] = drupal_get_js();
}