When creating an autocomplete form in a custom module how do tell Drupal what modules I need?

Question

I want to create an auto-complete form in my custom module that will be loaded in a block. Drupal doesn't seem to be loading the necessary Javascript libraries to work properly. How do I know what needs to be loaded and how/where do I tell Drupal to load these libraries?

hook_block_view:

function my_module_block_view($delta = '') {
    //The $delta parameter tells us which block is being reqested.
    switch ($delta) {
        case 'my_module_my_block':
            $block['subject'] = t('Block Subject');
            $block['content'] = drupal_get_form('my_module_my_form');
            break;
    }

    return $block;
}

Form code:

function my_module_my_form($form, &$form_state) {   
    $form = array();

    $form['term'] = array(
        '#type' => 'textfield',
        '#autocomplete_path' => 'my-module-autocomplete'
    );

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

    return $form;   
}

The form loads, the field is there, but auto-complete isn't working :(

If I call the my-module-autocomplete path I do get a valid response back when compared with a Content Type edit form. The ajax spinner in the input field never appears so the ajax isn't being called.

Answer 1

See the examples module for a straight forward AJAX Example.

Answer 2

Genuinely non-trivial, so here are some links:

Drupal AJAX API. Alternately, drupal_add_js()