Unable to capture the form select value , php - php

Question

After reading a number of posts on here, on how to capture the Select values in my html form, I understand the principle but I cant seem to execute it flawlessly in my code below.
$selected_val isn't being appended. perhaps its empty? What am I missing? Thanks in advance.
Desired result:
test#test.com is an A-user ,
Current result:
test#test.com is an ,
Here is how my HTML form looks:
<form method="POST" class="subscription-form form-inline id="subscribe" role="form">
<h4 class="subscription-success"><i class="icon_check"></i> Thank you for requesting... </h4>
<h4 class="subscription-error">Something Wrong!</h4>
<select name="usertype" class="form-control input-box">
<option selected value="A-user">I'm an A user</option>
<option value="B-user">I'm an B user</option>
<option value="C-user">I'm an C user</option>
</select>
<input type="email" name="email" id="subscriber-email" placeholder="Your Email" class="form-control input-box">
<button type="submit" name="submit" id="subscribe-button" class="btn btn-default standard-button">Submit</button>
</form>
Here is my php:
<?php
if ( isset($_POST['email']) && filter_var($_POST['email'], FILTER_VALIDATE_EMAIL) ) {
$selected_val = $_POST['usertype']; // Storing Selected Value In Variable
$e_mail = $_POST['email'] . " is a " . $selected_val . " ," . "\n";
file_put_contents('email-list.txt', $e_mail, FILE_APPEND | LOCK_EX);
}
?>

Answer 1

Your form is missing method attribute
Post method should be there
<form action="your.php" method="post">

Answer 2

<form> element should have method attribute like
<form method="POST" class="subscription-form form-inline wow fadeInRight animated" data-wow-offset="10" data-wow-duration="1.5s" id="subscribe" role="form">
And NOTE in your PHP code, the user will click the submit button so check
if ( isset($_POST['submit'])) {
selected_val = $_POST['usertype']; // Storing Selected Value In Variable
$e_mail = filter_var($_POST['email'], FILTER_VALIDATE_EMAIL);
$e_mail = $e_mail . " - is a - " .$selected_val . " ," . "\n";
file_put_contents('email-list.txt', $e_mail, FILE_APPEND | LOCK_EX);
}