PHP sessions

// i have tried a few options - url parameter /?client_feddback=1

//option 1

<?php
session_start();

$_SESSION["client_feedback"] = $_GET['client_feedback'];

if( isset( $_SESSION["client_feedback"] ) != "" ) {
    ?> <style type="text/css">#form__feedback {display:block!important}</style> <?php
} else {
    ?> <style type="text/css">#form__feedback {display:none!important}</style> <?php
}
?>

//option 2

<?php
session_start();

if (isset($_GET["client_feedback"]) && $_GET["client_feedback"] !== "") {
$_SESSION["client_feedback"] = $_GET['client_feedback'];
}

if (isset($_SESSION["client_feedback"]) {
    ?> <style type="text/css">#form__feedback {display:block!important}</style> <?php
} else {
    ?> <style type="text/css">#form__feedback {display:none!important}</style> <?php
}
?>