What are the best practices for handling frame navigation using PHP and JavaScript?

When handling frame navigation using PHP and JavaScript, it is important to ensure that the navigation is smooth and seamless for the user. One common issue is maintaining the state of the page when navigating between frames. To solve this, you can use PHP to store the state of the page in session variables and JavaScript to update the frames accordingly.

<?php
session_start();

// Check if a specific frame is being loaded
if(isset($_GET['frame'])) {
    $_SESSION['current_frame'] = $_GET['frame'];
}

// Display the appropriate frame based on the session variable
if(isset($_SESSION['current_frame'])) {
    echo '<iframe src="' . $_SESSION['current_frame'] . '"></iframe>';
} else {
    echo '<iframe src="default_frame.php"></iframe>';
}
?>