<a href="index.php">Index</a><br>
    <form name="registrationForm" method="post" onsubmit="return validateForm()">
        <input type="text" class="form-control" placeholder="Enter username" name="username"><font color="red">*</font>
        <input type="text" class="form-control" placeholder="Enter email address" name="email"><font color="red">*</font>
        <input type="password" class="form-control" placeholder="Enter password" name="password"><font color="red">*</font>
        <input type="text" class="form-control" placeholder="Enter first name" name="first"><font color="red">*</font>
        <input type="text" class="form-control" placeholder="Enter last name" name="last"><font color="red">*</font>
        <input type="text" class="form-control" placeholder="Enter zip code" name="zip"><font color="red">*</font>
        <input class="btn btn-default" type="submit" name="submit" value="Submit">
    </form>

    <?php
    ini_set('display_errors',1);
    error_reporting(E_ALL);

    if (isset($_POST['submit'])){
    //if($_SERVER["REQUEST_METHOD"] == "POST"){
        $username = $_POST["username"];
        $email = $_POST["email"];
        $password = $_POST["password"];
        $first = $_POST["first"];
        $last = $_POST["last"];
        $zip = $_POST["zip"];

        // Check connection
        if ($db->connect_error) {
            die("Connection failed: ".$db->connect_error);
        }

        //flag to detect if the username exists in db
        $flag = 0;
        $sql = "SELECT username FROM users WHERE username = '".$username."';";
        $result = $db->query($sql);
        if ($result->num_rows > 0) {
            $flag = 1;
        }

        //If the username already exists then alert the user, else insert the record to the db and send user to login.php
        if ($flag == 1){
            echo "<script>alert("Sorry, that username is already taken. Please choose another.");</script>";
        }
        else {
            $sql = "INSERT INTO users (first, last, username, email, password, zip) VALUES ('".$first."', '".$last."', '".$username."', '".$email."', '".$password."', '".$zip."')";
            if ($db->query($sql) === TRUE) {
                //echo "Registration successful";
                //$filename = "/profiles/".$username.".php";
                //chmod($filename,0777);
                echo 'Current script owner: ' . get_current_user() . "<br>";
                echo 'posix: '.posix_getuid()."<br>";
                echo getcwd()."<br>";
                $last_line = system('whoami', $retval);
                echo $last_line . " " . $retval;
                $file = fopen("profiles/test.txt", "w") or die("Unable to open file!");
                //$txt = "This is a user profile for ".$username;
                //fwrite($file, $txt);
                fclose($file);
                //header('Location: login.php');
            } else {
                echo "Registration error, please try again later.";
            }
        }
    }
    $db->close();
    ?>
</body>