How to add cursor focus on first Gravity Forms field validation error

add-cursor-focus-first-gf-field-validation-error-all-forms.php

<?php
add_filter( 'gform_pre_render', 'hjs_add_script_block' );
function hjs_add_script_block( $form ) { ?>
	<script type="text/javascript">
		jQuery(document).bind('gform_post_render', function() {  
			jQuery('li.gfield.gfield_error:first input').focus();
		});
	</script>
	<?php 
	return $form;
}

add-cursor-focus-first-gf-field-validation-error-script.js

<script type="text/javascript">
  jQuery(document).bind('gform_post_render', function() {  
    jQuery('li.gfield.gfield_error:first input').focus();
  });
</script>

add-cursor-focus-first-gf-field-validation-error.php

<?php
// Replace 9 with form ID
add_filter( 'gform_pre_render_9', 'hjs_add_script_block' );
function hjs_add_script_block( $form ) { ?>
	<script type="text/javascript">
		jQuery(document).bind('gform_post_render', function() {  
			jQuery('li.gfield.gfield_error:first input').focus();
		});
	</script>
	<?php 
	return $form;
}