Mailingform tutorial from kirupa

Hello i desided to follow the tutorial on the kirupa website
http://www.kirupa.com/web/php_contact_form.htm

Now here are my scripts that i made:

My own contact.htm called mailinglist.htm

<html>

<head>
<meta http-equiv="Content-Language" content="en-us">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>. . . : : : LEOMORENO : : MAILINGLIST : : : . . .</title><style type="text/css">
<!--
body,td,th {
	font-family: Century Gothic;
	font-size: 12px;
	color: #36301C;
}
body {
	background-color: #D57791;
	margin-left: 10px;
	margin-top: 10px;
	margin-right: 0px;
	margin-bottom: 0px;
	background-image: url(images/BGmailing.png);
	background-repeat:no-repeat;
	background-attachment:fixed
}
-->
</style>
</head>

<body>

<form method="POST" action="mailer.php">
	<p>your name:<br>
	  <input type="text" name="name" size="19">
	  <br>
	  <br>
	your email:<br>
	<input type="text" name="email" size="19">
	<br>
	<br>
  	your favorite background color:<br><br>
      <input type="checkbox" name="check[]" value="Groen">
      green<br>
      <input type="checkbox" name="check[]" value="Blauw">
      blue <b></b><br>
      <input type="checkbox" name="check[]" value="Geel">
      yellow <b></b><br>
      <input type="checkbox" name="check[]" value="Roze">
      pink <b></b><br><br>
	subscribe or unsubscribe for the mailinglist:<br>
	<br>  
      <input type="radio" value="yes" name="radio">
      subscribe
      <input type="radio" value="no" name="radio"> 
  unsubscribe<br><br>
      <input type="image" src="images/sendmebut.png" value="Submit" name="submit">
  </p>
</form>

</body>

</html>

and my php form i rebuild: mailer.php

<style type="text/css">
<!--
body,td,th {
	font-family: Century Gothic;
	font-size: 12px;
	color: #36301C;
}
body {
	background-color: #D57791;
	margin-left: 10px;
	margin-top: 10px;
	margin-right: 0px;
	margin-bottom: 0px;
	background-image: url(images/BGmailing.png);
	background-repeat:no-repeat;
	background-attachment:fixed
}
-->
</style>
<?php
if(isset($_POST['submit'])) {

	$to = "[email protected]"; 
	$subject = "Mailinglist subscription";
	$name_field = $_POST['name'];
	$email_field = $_POST['email'];
	$option = $_POST['radio'];

	foreach($_POST['check'] as $value) {
		$check_msg .= "Checked: $value
";
	}
	
	$body = "From: $name_field
 E-Mail: $email_field
 $check_msg Option: $option
";

	echo "Data has been submitted to Leo Moreno";
	mail($to, $subject, $body);
	
} else {
	echo "ERROR: No data has been submitted to Leo Moreno";
}
?>

Now i tested it on 3 servers (with mac)
Safari 1.2.4
Firefox 1.0
Internet Explorer 5.2 for mac

Now only the Firefox will send it to my emailbox.

Is there a mistake i’m making because the form kirupa made works fine on safari and IE

Thanx