Adding a jQuery script to wordpress Admin

Solution:1

Be aware that the jQuery included with WordPress runs in NoConflict Mode as far as I know, meaning that there is no $, but instead jQuery. That’s probably why you deregistered the builtin jQuery and used the one from Google CDN. That one probably doesn’t run in that mode.

I don’t have any experience with wordpress, so I might make a mistake here. Just be sure that the builtin jQuery is available and load your script.

function my_script() {
    if (!is_admin()) {
        wp_enqueue_script('custom_script', get_bloginfo('template_url').'/js/myScript.js', array('jquery'));
    }
    if(is_admin()){
        wp_enqueue_script('custom_admin_script', get_bloginfo('template_url').'/js/admin_script.js', array('jquery'));
    }   
}

Change your admin_script.js to use jQuery instead $.

jQuery(document).ready(function(){
    alert("Hello"); 
});

See if that works for you. If you like to use $ you could probably write var $ = jQuery; at the top of your admin_script.js.

Solution:2

You can do like this

<?php add_action( 'admin_enqueue_scripts', 'function_name' ); ?>

This can be used like this

<?php 
  add_action( 'admin_enqueue_scripts', 'load_custom_script' ); 
  function load_custom_script() {
      wp_enqueue_script('custom_js_script', get_bloginfo('template_url').'/js/custom-script.js', array('jquery'));
  }
?>