<?php
if(isset($_POST['submit']))
{
    $username = $_POST['username'];
    $password = $_POST['password'];
    $expiry = new Datetime('+1 year');
    setcookie('username', $username, $expiry->getTimestamp());
    setcookie('password', $password, $expiry->getTimestamp());
    echo $_COOKIE['username'].", ".$_COOKIE['password'];
}
?>
<form action="#" method="post">
    <label for="username">Username: </label><input type="text" name="username"><br />
    <label for="password">Password: </label><input type="text" name="password"><br />
    <input type="submit" name="submit" value="Submit">
</form>
<div class="parent">
    <?php
        if(!empty($_COOKIE)) {
            echo $_COOKIE['username'];
        }
        else {
            echo '';
        }
    ?>
</div>
<style>
    .parent {
        background-color: red;
        width: 500px;
        height: 500px;
        text-align: center;
        line-height: 500px;
    }
</style>