Website register wont work.

[Corlet]

I downloaded a open source php game script and the signup doesnt work. When you enter your details and click register it just refreshses the page and doesn register your account. I dont know what information to paste here for anyone to see whats wrong with it because I cant do scripting myself, but I know a tiny bit from editing them. Heres the sign up form, if you need any other pages just add a comment.

 

<?php include("head.php"); ?>



<center>name</center>

<form method=post action=signup.php?action=register>
<table>
<tr><td>Username:</td><td><input type=text name=user></td></tr>
<tr><td>Email:</td><td><input type=text name=email></td></tr>
<tr><td>Pass:</td><td><input type=password name=pass></td></tr>
<tr><td>Verify Pass:</td><td><input type=password name=vpass></td></tr>
<tr><td colspan=2 align=center><input type=submit value=register></td></tr>
</table>
</form>

<?php
if ($action == register) {
if (!$user || !$pass || !$email || !$vpass ) {
	print "You must fill out all fields.";
	include("foot.php");
	exit;
}
$dupe1 = mysql_num_rows(mysql_query("select * from players where user='$user'"));
if ($dupe1 > 0) {
	print "Someone already has that username.";
	include("foot.php");
	exit;
}
$dupe2 = mysql_num_rows(mysql_query("select * from players where email='$email'"));
if ($dupe1 > 0) {
	print "Someone already has that email.";
	include("foot.php");
	exit;
}
if ($pass != $vpass) {
	print "The passwords do not match.";
	include("foot.php");
	exit;
        }
        $ip = "$HTTP_SERVER_VARS[REMOTE_ADDR]";
        $ipcheck = mysql_num_rows(mysql_query("SELECT * FROM players WHERE IP = '$ip'"));
  if ($ipcheck > 0) { 
  Print "You can only have 1 account per person.";
     include("foot.php");
       exit;  
       } 
$x = strip_tags($ref);
$user = strip_tags($user);
$pass = strip_tags($pass);
mysql_query("insert into players (user, email, pass) values('$user','$email','$pass')") or die("Could not register.");
print "You are now registered to play, $user. Please login now.";
}
?>

<?php include("foot.php"); ?>

[marcus]

$action is not defined.

[revraz]

Do you have register globals turned on?  If not, you need to change the variables that depend on it to $_POST and $_GET