What are the potential pitfalls of using JavaScript to handle the back button functionality in PHP forms?

When using JavaScript to handle the back button functionality in PHP forms, one potential pitfall is that users may have JavaScript disabled in their browsers, rendering the functionality ineffective. To solve this issue, you can implement a server-side solution by checking the referrer URL in the PHP code to determine if the user has navigated back to the form.

<?php
// Check if the referrer URL is the form page
if(isset($_SERVER['HTTP_REFERER']) && strpos($_SERVER['HTTP_REFERER'], 'form.php') !== false) {
    // Handle the back button functionality here
    // For example, pre-fill the form fields with the previous values
}
?>