Q:

PHP in HTML Form Action Tag

First PHP page, so this is likely a problem surfacing out of something stupid I'm missing, but I'm not sure what. I'm following the tutorial on W3Schools to create a form with protection from XSS, but when I use the code<form method="post" action="<?php echo $_SERVER['PHP_SELF'); ?>">, it is parsed such that the first > is associated with the form tag, so the quotes are mismatched, and the action doesn't complete correctly. 
This is what the page looks like:

EDIT:
Full Code Below
<body>
<?php
    $fname = $lname = $email = $student = "";
    if($_SERVER["REQUEST_METHOD"] == "POST")
    {
        $fname = $_POST["fname"];
        $lname = $_POST["lname"];
        $email = $_POST["email"];
        switch($_POST["student"])
        {
            case "u":
                $student = "Undergraduate";
                break;
            case "g":
                $student = "Graduate";
                break;
            default:
                $student = "Non-Student";
        }   
    }
?>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'); ?>">
    <p>First Name: <input type="text" name="fname"> </p>
    <p>Last Name: <input type="text" name="lname"> </p>
    <p>Email: <input type="email" name="email"> </p>
    <p>Student Status: <select name="student">
                        <option value="u">Undergraduate</option>
                        <option value="g">Graduate</option>
                        <option value="x">Non-Student</option>
                    </select> </p>
    <input type="submit" value="Submit">
</form>

<?php
    echo "<h3>Input:</h3>"
    echo "Name: " . $fname . " " . $lname . "<br>";
    echo "Email: <a href=mailto:" . $email . ">" . $email . "</a><br>";
    echo "Student: " . $student;
?>
</body>

A:

.html files do not get parsed like .php files do, therefore you will need to install a Webserver on your system.
Sidenote: You can instruct Apache to treat .html files as PHP, if and when the time comes that you want to do this, it is possible.

Here is an article on Stack: Using .htaccess to make all .html pages to run as .php files?

.php files cannot be run directly from a web browser, unless they are parsed and running off a server or a hosted site.
They require to be accessed as http://localhost/file.php from a local machine.
Depending on your platform, you can use Xampp which runs on Windows, Mac and Linux.

https://www.apachefriends.org/

Wamp:

http://www.wampserver.com/en/
http://www.easyphp.org/

Mamp (Mac):

https://www.mamp.info/

Plus, you have a few syntax errors.
action="<?php echo $_SERVER['PHP_SELF'); ?>">
                                      ^

that should be a square bracket, rather than a parentheses.
action="<?php echo $_SERVER['PHP_SELF']; ?>">

and echo "<h3>Input:</h3>" is missing a closing semi-colon.
Those would throw/cause a parse error.

