Problems saving functions.php file

HI there, I need to add an extra hook to the functions.php but every time I click save the screen goes blank.

Here’s the code I need to add:
<?php

/**
* If you need to make some of the GravityView search fields required before search is submited
* – add as many lines as you need to define which fields are required
* e.g. -> jQuery(‘#gv_search_XYZZ’).prop(‘required’, true );
*
* Add this gist to your theme functions.php
*
*/

add_action(‘gravityview_after’, ‘my_theme_make_search_fields_required’ );

function my_theme_make_search_fields_required() {
?>
<script>
//define here the search fields that are required
jQuery(‘#gv_search_2247’).prop(‘required’, true );

// validation magic
jQuery(‘form.gv-widget-search’).submit( function(e) {
e.stopPropagation();
var isValid = true;
jQuery(‘.gv-widget-search input:required’).each( function(){
if( jQuery(this).val() === ” ) {
isValid = false;
}
});
return isValid;
});
</script>
<?php
}

What I’m doing wrong?
Please let me know how to fix it.