why does drupal_get_path() not work in my code? somehow drupal_get_path is not working I'm my module in my function vacancies_manage_test_pager()

drupal_get_path() returns notting ( empty string or NULL or something ) when I DSM(drupal_get_path('module','vacancies_manage')); I get an empty message

module code:

/**
 * Implements hook_permission
 */
function vacancies_manage_permission() {
    return array(
        'manage own vacancies' =&gt; array(
            'titel' =&gt; t('Manage own vacancies'),
            'description' =&gt; t('Allows users use the own vacancies page'),
        ),
    );
}

/**
 * Implements hook_menu
 */
function vacancies_manage_menu(){
  $items = array();

    // Test items
    $items['vacancies_manage'] = array(
      'title' =&gt; 'Vacatures beheren',
      'description' =&gt; 'Eigen vacatures beheren.',
      'type' =&gt; MENU_NORMAL_ITEM,
      'page callback' =&gt; 'vacancies_manage_test_pager',
      'access arguments' =&gt; array('manage own vacancies'),
    );   

    // needed for jQuery / ajax callback
    $items['vacancies_manage/callback'] = array(
      'title' =&gt; 'vacatures beheer Callback',
      'type' =&gt; MENU_CALLBACK,
      'page callback' =&gt; '_vacancies_manage_test_pager_callback',
      'access arguments' =&gt; array('manage own vacancies'),
    );

    return $items;
}


function vacancies_manage_test_pager() {
    drupal_add_js(drupal_get_path('module', 'vacanies_manage') . '/jquery.url.js' );
    drupal_add_js(drupal_get_path('module', 'vacanies_manage') . '/vacanies_manage.js' );
    drupal_add_js('initializeTable();', 'inline');

    return ('&lt;div id="table-container"&gt;&lt;/div&gt;');
}

function _vacancies_manage_test_pager_callback() {

    global $user;

    header("Content-type: text/html");
    header("Expires: Wed, 29 Jan 1975 04:15:00 GMT");
    header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
    header("Cache-Control: no-cache, must-revalidate");
    header("Pragma: no-cache");


    // build header for HTML table

    $header = array (
        array('data' =&gt; t('Titel')),
        array('data' =&gt; t('Aangemaakt op')),
        array('data' =&gt; t('Gepubliceerd')),
        //array('data' =&gt; t('Dupliceer')),
    );

    // query db for user nodes
    $query = db_select('node','n');
    $query-&gt;fields('n', array('nid','title','created','status'));

    if($user-&gt;uid !== "1" ) {
        $query-&gt;condition('n.uid', $user-&gt;uid);
    }

    $results = $query-&gt;execute();
    dsm($results);

    // display nodes
    $rows = array();

    foreach($results as $vacancy) {
        $rows[] = array(
            'data' =&gt; array(
                $vacancy-&gt;title,
                $vacancy-&gt;created,
                ($vacancy-&gt;status == 1?t('Ja'):t('Nee')),
                //dupliceer
            ),
        );
    }

    //Theme the html table
    $html = theme('table',
        array(
            'header' =&gt; $header,
            'rows' =&gt; $rows,
            'sticky' =&gt; TRUE, // Optional to indicate whether the table headers should be sticky 
            'empty' =&gt; 'U heeft geen vacatures.', // Optional when no results
        )
    );

    $html .= theme('pager',
        array(
            'tags' =&gt; array(),
        )
    );

    die($html);
}
You've spelled vacanies_manage wrong....  (same with your js file, too [and titel in your permissions])