<?php
session_start ();
?>
<form method="POST" action="./form.php">
<input type="password" name="p4"></input>
<input type="submit"></input>
</form>
<?php
setcookie ("c4", "Hallo", time () + 1200);
echo htmlentities ($_COOKIE ["c4"]) . "<br>\n";
echo htmlentities ($_COOKIE ["c4a"]) . "<br>\n";
echo htmlentities ($_POST ["p4"]) . "<br>\n";
session_destroy ();
?>