PHP에서 자체 제출 양식을 만드는 방법은 무엇입니까?

<code class="php"><form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
    ... (form fields) ...
    <input type="submit" value="Submit">
</form></code>

<code class="php"><form method="post">
    ... (form fields) ...
    <input type="submit" value="Submit">
</form></code>

<code class="php"><?php
if (!empty($_POST)) {
    echo "Welcome, " . htmlspecialchars($_POST["name"]) . "!<br>";
    echo "Your email is " . htmlspecialchars($_POST["email"]) . ".<br>";
} else {
    ?>
    <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
        Name: <input type="text" name="name"><br>
        Email: <input type="text" name="email"><br>
        <input type="submit" value="Submit">
    </form>
    <?php
}
?></code>