Ho questo codice:

codice:
html>
<body>




<?php
if ($_POST['submit']) {
$required_fields = explode(",", $_POST['required']);

$error = 0;

foreach($required_fields as $fieldname) {
if ($_POST[$fieldname] == "") {
$error++;
}
}

if ($error == 0) {
if (strstr($_POST['email'], "@") and strstr($_POST['email'], ".")) {

mail("youremail@your.com" , "Message from Web Form", $_POST['message'], "From: $_POST[name] <$_POST[email]>");

print "<html><body>Thank you for submitting your comments $_POST[name]!</body></html>";
exit;

} else { 
$errormessage = "The email address you entered does not appear to be valid
";
}

} else {
$errormessage = "[b]You have left some required fields in the form blank! Please fill in the form completely.";
}
}
?>

<?=$errormessage?>



<form action="<?=$_SERVER['PHP_SELF']?>" method="post">
<table width="500" border="0" cellpadding="5" cellspacing="0">
<tr><td>Your name:</td><td><input type="text" name="name" value="<?=$_POST['name']?>"></td></tr>
<tr><td>Your email:</td><td><input type="text" name="email" value="<?=$_POST['email']?>"><td><tr>
<tr><td>Your message:</td><td><textarea name="message"><?=$_POST['message']?></textarea></td></tr></table>
<input type="hidden" name="required" value="name,email,message">
<input type="submit" name="submit" value="submit">

</body></html>
ma mi da questo errore subito:

Notice: Undefined index: submit in c:\inetpub\wwwroot\php\mail.php on line 6

Notice: Undefined variable: errormessage in c:\inetpub\wwwroot\php\mail.php on line 35

e lo stesso all interno degli input come value.
Dove sbaglio?