[php] how to pass value from one php page to another using session

I can pass values form one page to another but I need to pass value like this,

Page 1:

Page4.php

Page3.php

I need to pass the value in a text field in the Page1.php to a text field in Page2.php, since the form is not directly redirectly to page2, I am unable to pass the value, I tried session, form post method and few other methods but I am yet to succeed.

I would be very happy if you can help me with the code or some suggestions.

Thanks!

Edit..........

I found the answer, thanks for the help, it was actually a careless mistake on my part, I used $_post instead of $_session.

Its working now.

Thanks for the help.

Solution using just POST - no $_SESSION

page1.php

<form action="page2.php" method="post">
    <textarea name="textarea1" id="textarea1"></textarea><br />
    <input type="submit" value="submit" />
</form>

page2.php

<?php
    // this page outputs the contents of the textarea if posted
    $textarea1 = ""; // set var to avoid errors
    if(isset($_POST['textarea1'])){
        $textarea1 = $_POST['textarea1']
    }
?>
<textarea><?php echo $textarea1;?></textarea>

Solution using $_SESSION and POST

page1.php

<?php

    session_start(); // needs to be before anything else on page to use $_SESSION
    $textarea1 = "";
    if(isset($_POST['textarea1'])){
        $_SESSION['textarea1'] = $_POST['textarea1'];
    }

?>


<form action="page1.php" method="post">
    <textarea name="textarea1" id="textarea1"></textarea><br />
    <input type="submit" value="submit" />
</form>
<br /><br />
<a href="page2.php">Go to page2</a>

page2.php

<?php
    session_start(); // needs to be before anything else on page to use $_SESSION
    // this page outputs the textarea1 from the session IF it exists
    $textarea1 = ""; // set var to avoid errors
    if(isset($_SESSION['textarea1'])){
        $textarea1 = $_SESSION['textarea1']
    }
?>
<textarea><?php echo $textarea1;?></textarea>

WARNING!!! - This contains no validation!!!