I'm trying to understand session variables by trying this code. For the purpose of the test, I created 3 pages and tried to pass the session variables around. I noticed that, the session variable is not populated in the 3rd page. I have searched to see where the problem is and I'm yet to figure it out.
page1
<!DOCTYPE html>
<html lang="en">    
    <head>
        <meta charset="UTF-8">
        <title>Bio Data</title>
    </head> 
    <body>
        <form action="process.php" method="post">
            <label for="fst_name">
                First Name
                <input type="text" name="fst_name" id="fst_name">
            </label>
            <label for="lst_name">
                Last Name
                <input type="text" name="lst_name" id="lst_name">
            </label>
            <input name="submit" type="submit" value=" Login ">
        </form>
    </body>
</html>
page2
<?php
session_start();
if (isset($_POST["submit"])){           
    $_SESSION['fst_name'] = $_POST['fst_name'] ;
    $_SESSION['lst_name' ] = $_POST['lst_name'] ;
    header("location:display.php");
}else{
    echo "Error";
}
page3
<?php
session_start();
echo $_SESSION['fst_name'];
?>
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Biodata Display</title>
    </head>
    <body>
        <table>
            <tr>
                <td><?php echo "Hello " .  $_SESSION['fst_name']; ?></td>
                <td><?php echo $_SESSION['lst_name']; ?></td>
            </tr>
        </table>    
    </body>
</html>
 
    