embedding js on wp admin footer problem

Hi, I am currently having problem to embed external js to WP back-end footer. I used wp_enqueue_script function for this purpose, as this function as I know is the best practice of adding js to a WP generated page and it called via admin-footer-$page hook. Somehow this workaround not giving any results. But if I simply echo the scripts replacing the wp_enqueue_scripts it does work perfectly. I only want to know if there is problem with the way of adding scripts to footer via wp_enqueue_script or there is another appropriate way beside just doing echo. Here is my code (on plugin):

http://wordpress.pastebin.com/1weeYNia