i'm using the watcher module and would like to place the watcher action into a block (the ajaxified "watch this" "stop watching this" button)

i tried to paste this update to some old code into a block and it ain't working - any ideas? missing something for rendered output? i have no idea...
should it be making use of:
print drupal_render($node['field_name']);

here's what i have in there right now with the error on 3, and "watcher" is the field name

if (arg(0) == 'node' && is_numeric(arg(1))) {
$node = node_view(node_load(arg(1));