function custom_menu() {
  $items = array();

  $items['test/%ctools_js'] = array(
    'page callback' => 'test_page',
    'page arguments' => array(1),
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  return $items;
}

function test_page($js = NULL) {
  $block = block_load('system', 'powered-by');
  $block_content = _block_get_renderable_array(_block_render_blocks(array($block)));

  $output = render($block_content);
  $title = 'Our title';
  if ($js) {
    ctools_include('ajax');
    ctools_include('modal');
    ctools_modal_render($title, $output);
    // above command will exit().
  }
  else {
    drupal_set_title($title);
    return $output;
  }
}

function custom_init() {
  if (drupal_is_front_page()) {
    ctools_include('modal');
    ctools_modal_add_js();

    // Create our own javascript that will be used to theme a modal.
    $custom_style = array(
      'custom-modal-style' => array(
        'modalSize' => array(
          'type' => 'fixed',
          'width' => 1100,
          'height' => 325,
          'contentRight' => 0,
          'contentBottom' => 0,
        ),
        'modalOptions' => array(
          'opacity' => .8,
          'background-color' => '#000000',
        ),
        'animation' => 'fadeIn',
        'modalTheme' => 'custom_modal',
        'closeImage' => theme('image', array('path' => ctools_image_path('modal-close.png', 'custom'), 'alt' => t('Close window'), 'title' => t('Close window'))),
      ),
    );

    // Add the settings array defined above to Drupal 7's JS settings:
    drupal_add_js($custom_style, 'setting');
    // The function below assumes the custom_modal.js file resides in [module_dir]/js
    ctools_add_js('custom_modal', 'custom');
  }
}

(function ($) {
    Drupal.theme.prototype.custom_modal = function () {
    var html = ''
    html += '  <div id="ctools-modal">'
    html += '    <div class="ctools-modal-content">' // panels-modal-content
    html += '      <div class="modal-header">';
    html += '        <a class="close" href="#">';
    html +=            Drupal.CTools.Modal.currentSettings.closeText + Drupal.CTools.Modal.currentSettings.closeImage;
    html += '        </a>';
    html += '        <span id="modal-title" class="modal-title"> </span>';
    html += '      </div>';
    html += '      <div id="modal-content" class="modal-content">';
    html += '      </div>';
    html += '    </div>';
    html += '  </div>';

    return html;
  }
})(jQuery);