how ajax function in wp plugin can load on user side (for viewrs)

i'm developing wp plugin in which when user enter id to get post against that id. that is working fine on admin side. i followed example to get data by ajax call

http://dobsondev.com/2015/06/12/wordpress-ajax-example/

but now i'm trying to do on customer side where anyone can enter id and get result. I removed function which was using to create page on admin side. rest of that i have 4 function named

hello_word() , ajax_script(), ajax_handler()

i tried to use following add_Action to register but it was not working

    add_action( 'admin_footer', 'ajax_script' );

then i tried following to register ajax_script

    add_action( 'wp_ajax_my_action', 'ajax_script' );
    add_action( 'wp_ajax_nopriv_my_action', 'ajax_script' );

hello_word() function contain code for text field and button i call hello_word() function from template file, it displays correctly, but ajax is not working when i click button , the issue i found is that ajax_script() is not loaded and in debugging mode in source there is nothing when i click button.

so how to load ajax function correctly. while i'm calling hello_word() from template file.