Also try changing:
Code:
$link = "INSERT INTO users VALUES ('$name','$email',NOW(),'subscribed','0','')";
$res= mysql_query($link) or die(mysql_error());
if ($res)
die("Email Succesfully Registerted.");
to:
Code:
$link = "INSERT INTO users VALUES ('$name','$email',NOW(),'subscribed','0','')";
$res= mysql_query($link) or die(mysql_error());
if ($res)
include("main.php");
Then add the message to the top of main.php.
I dont have the your site's code so this is hard to tell excatly what your problem is but that would be what I'd try.
If you want to upload and PM me your site's script I may be bale to help you more.