Help to change D6 code to D7 code

In Drupal 6 I had it working where a OG group admin (worked in non-groups as well) could post a question above the shoutbox.

This is the set up:

1. I added a field in the content type of the group. Mine is called field_speak_up_topic. Admins could change the question as often as they liked.

2. Then a Drupal block was created with the code below:

   <?php
$node = menu_get_object();
$block = module_invoke('shoutbox', 'block', 'view', '0');
print '<div id="speakup_question">'. $node->field_speak_up_topic[0]['value'] .'</div>';
print '<div id="speakup_box">'. $block['content'] .'</div>';
?>
3. Then the block was placed in the panel node of the group or page.

This worked great until I upgraded to Drupal 7. Now it doesn't work. The menu_get_object is still in the D7 API. Maybe the module_invoke changed or the way to get the field content into $block?

Don't know why. Any ideas?