Title: New to javascript in wordpress
Last modified: January 6, 2019

---

# New to javascript in wordpress

 *  [ololi01](https://wordpress.org/support/users/ololi01/)
 * (@ololi01)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/)
 * Hi
 * I’m trying to learn how to use javascript in wordpress and doing this by doing
   some really simple JS-functions. However have run into a problem when placing
   the script in an external file.
 * (not sure if this is the correct forum, but starting here)
 * in my external file, called myScript.js I have this code:
 *     ```
       function myFunction() {
         document.getElementById('demo').innerHTML = "Paragraph changed.";
       }
       ```
   
 * in functions php
 *     ```
       function your_scripts() {
                           wp_register_script('myFunction', '/js/myScript.js', false);
                           // This registers your script with a name so you can call it to enqueue it
                           wp_enqueue_script( 'myFunction' );
                           // enqueuing your script ensures it will be inserted in the propoer place in the header section
                   }
                   add_action('wp_enqueue_scripts', 'myFunction');
       ```
   
 * And in my header-php
 *     ```
       <p id="demo">A Paragraph.</p>
       <button type="button" onclick="myFunction()">Try it</button>
       ```
   
 * So the myScript.js seems to be loading but when clickin the button I get the 
   error _myFunction not defined_
 * cannot understand what I’ve done wrong..
    -  This topic was modified 7 years, 4 months ago by [Jan Dembowski](https://wordpress.org/support/users/jdembowski/).

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [RossMitchell](https://wordpress.org/support/users/rossmitchell/)
 * (@rossmitchell)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11057204)
 * By replacing the theme “header.php” file with your own, you are disrupting the
   WordPress page assembly flow, lots of things you expect to happen just will not
   get started. So reinstate your theme’s header.php file please.
    Then to get your
   paragraph with id=”demo” and your button, put them into the text of a page. View
   the page and check with your browser inspector what has been loaded.
 *  Thread Starter [ololi01](https://wordpress.org/support/users/ololi01/)
 * (@ololi01)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11057234)
 * Thanks for your reply! 🙂 However, not really sure on what u mean that I’m replacing
   the php-file with my own? I’m edititng the actual header.php pf the theme.
 *  Thread Starter [ololi01](https://wordpress.org/support/users/ololi01/)
 * (@ololi01)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11057239)
 * But your recommendation made it work 🙂
 *  Thread Starter [ololi01](https://wordpress.org/support/users/ololi01/)
 * (@ololi01)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11057241)
 * Thanks, now I just have to backtrack what happened to understand it 🙂
 *  [OpensaurusRex](https://wordpress.org/support/users/deth4uall/)
 * (@deth4uall)
 * [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11067341)
 * Try using `add_action('wp_enqueue_scripts', 'your_scripts');`. The `add_action`
   function is expecting the `callback` that you are using to pass the enqueueing.

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘New to javascript in wordpress’ is closed to new replies.

 * In: [Developing with WordPress](https://wordpress.org/support/forum/wp-advanced/)
 * 5 replies
 * 3 participants
 * Last reply from: [OpensaurusRex](https://wordpress.org/support/users/deth4uall/)
 * Last activity: [7 years, 4 months ago](https://wordpress.org/support/topic/new-to-javascript-in-wordpress/#post-11067341)
 * Status: not resolved

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