mail form not responding

[chechu]

Hey all,

This is the page I am working on, where the php mail form is not responding: test (http://www.lichaamengeest.be/AAtest.php).

This is the html, part of megamenu:

<li><a href="#" class="megamenu_drop">Contact</a>
<div class="dropdown_4columns dropdown_container">
<div class="col_12">
<p>Phasellus molestie facilisis orci ut bibendum. Aliquam accumsan eros sit amet metus egestas porta.</p>
<div class="contact_form">
<form METHOD="post" ACTION="AAtest.php">
<label for="name">Naam<span class="required"> *</span></label><br />
<input name="name" type="text" class="form_element" id="name" value="" autocomplete="off" />
<label for="email">Email<span class="required"> *</span></label><br />
<input name="email" type="text" class="form_element" id="email" value="" autocomplete="off" />
<label for="message">Bericht<span class="required"> *</span></label><br />
<textarea name="message" class="form_element" id="message"></textarea>
<div class="form_buttons">
<input type="submit" class="button" id="submit" value="verzend" />
<input type="reset" class="button" id="reset" value="annuleer" />
</div>
</form>
</div>
</div>
</div>
</li>



And this is the php:

<?php

if ($_POST["action"] == "send"){

if ($_POST[name] != "" and $_POST[email] != "" and $_POST[message] != "") {
mail ("b@me.com", "bericht via B",
"
Naam: ".$_POST['name']."
E-mail: ".$_POST['email']."
Bericht: ".$_POST['message']."

",
"From: ".$_POST['name']." <".$_POST['email'].">");

$subject = "bevestiging bericht aan B";

$msg = "
(Dit is een automatisch verzonden mail; gelieve niet te antwoorden.)

Beste $_POST[name],

Bedankt voor je bericht.
Je bericht is doorgestuurd; je mag binnen twee werkdagen een antwoord verwachten.

Vriendelijke groeten,
B

Dit was je bericht:
$_POST[message]
";

mail($_POST[email], $subject, $msg);

echo 'Dankjewel voor je bericht.<br>Een bevestiging is onderweg.';

}

else{
echo 'Bericht niet verzonden.<br>Gelieve alle velden in te vullen.';
}
}
?>

Could anyone take a look and explain why the mailform is not responding, please?
Thanks.