hook_search

I'm having a problem intercepting a search submitted in the "Search form" block. I have a module my_module where I created this hook function:

my_module_search($op = 'search', $keys = NULL) {
    switch ($op) {
        case 'name':
          // Label of the product search tab.
          return t('Productl Search');

        case 'search':
          drupal_goto('node/101');

I was expecting whenever a search is submitted, it will be redirected to node/101, but it's not as the search is submitted and I get the search results page. However, I have a menu option that opens a custom search page and when this search page is executed from this submit:

   $form['my_module_search']['submit'] = array(
            '#type' => 'submit',
            '#value' => 'Search'
    );

Then I am redirected to node/101. Shouldn't I be able to capture a search conducted in the Drupal Search block?