[Plugin: jQuery Hover Footnotes] Work but there are errors

When wp debug is enabled I see this notice:
Notice: wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or init hooks.
I don’t know how to correct this. I find only this plugin for footnote that works as I need.

http://wordpress.org/extend/plugins/jquery-hover-footnotes/