Wordpress If else statement to hide or show a div based on population a field

Question

First time poster. PHP idiot.

I need to (re)write code that will display a div if a field is entered but to hide it if it's empty. The field is populated using a custom field in the backend of Wordpress.

I wrote this code many years ago and it used to work but no longer does. My skill level is 0. This is it:

<?php
$video = get_post_meta($post->ID, 'video_file_name', true);
if ($video == '')
{ ?>
<div class="hide">
<!-- hide video -->
</div>

<?php } else { ?>
<div class="show">

This a javascript block that shows a video player.

<script src="this_code_is_hidden.js"> </script>
<div id="mediaspace">text will be replaced</div> 
<script type="text/javascript">   
jwplayer('mediaspace').setup({
'file': 'http://video.xxxxx.com.au/<?php the_field('video_file_name'); ?>',
"advertising": 
     {
    'client': "vast",
    'tag': google ad invocation code
  },
 'title': '<?php the_title(); ?>',
        'ga': {
        'idstring': '<?php the_title(); ?>',
        'label': '<?php the_title(); ?>'
    },
'image': '<?php the_field('poster_frame'); ?>', 
"sharing": {
    "link": "http://www.xxxxx.com.au"
},
'controlbar': 'bottom', 
'stretching': 'fill',     
'width': '100%', 
'aspectratio': '16:9',
'height': '332'
}); 
</script>
</div>
<?php } ?>

I've hidden some bits for security.

The theory is when ('video_file_name') is populated it will show the javascript block which will display a video.

I use CSS classes to either hide or show.

If anyone can shed some light I would be most appreciative. I've spent hours searching and trying but not clever enough to make it work.

I don't know if you can 'echo' a whole code block.

Thank you.