Code:
<?php 
include('header.php');
if(isset($_POST['register'])){
foreach($_POST as $key => $value) {
    $sec[$key] = filter($value);
}

$verificare1 = mysql_query("SELECT * FROM `users` WHERE `login`='{$sec['user']}' OR `email`='{$sec['email']}'");
$verificare = mysql_num_rows($verificare1);

if ($verificare > 0) {
$mesaj = "<div class=\"error\">ERROR: Username or email already registered!</div>";
}else if (!isUserID($sec['user'])) {
$mesaj = "<div class=\"error\">ERROR: Username is incorrect!</div>";
}else if(!isEmail($sec['email'])) {
$mesaj = "<div class=\"error\">ERROR: Enter a valid email address!</div>";
}else if (!checkPwd($sec['password'],$sec['password2'])) {
$mesaj = "<div class=\"error\">ERROR: Passwords do not match!</div>";
}else{
if(isset($_COOKIE['PlusREF'])){
$ref = $_COOKIE['PlusREF'];
$user1 = mysql_query("SELECT * FROM `users` WHERE `id`='{$ref}'");
$user = mysql_fetch_object($user1);
mysql_query("INSERT INTO `referals`(user,referal,date) values('{$user->login}','{$sec['user']}',NOW())");
}
$activare = rand(000000000, 999999909);
mail($sec['email'],"Activate your account","
Hello,

Thank you for your signup on our site. 

Click on this link to activate your account: 
{$site->site_url}/activate.php?cod={$activare}
    
Best Regards!","From: Site Admin <{$site->site_email}>");
$final = VisitorIP();
$passa = $sec['password'];
$passc = MD5($passa);
mysql_query("INSERT INTO `users`(email,login,IP,pass,passdecoded,ref,signup,activate) values('{$sec['email']}','{$sec['user']}','$final','$passc','$passa','{$ref}',NOW(),'{$activare}')")or die(mysql_error());
$mesaj = "<div class=\"success\">Registered! You need to confirm your email address now!</div>";
}}
?>    
<div class="block medium right">
            <div class="top">
                  <h1>Register</h1>
            </div>
            <div class="content"><div class="msg"><?echo $mesaj;?></div>
<form action="" method="post">
                      <fieldset>
                         <p>
                             <label>Username</label><br/>
                             <input class="text big" type="text" value="" name="user"/>
                         </p>
                         <p>
                             <label>Email</label><br/>
                             <input class="text big" type="email" value="" name="email"/>
                         </p>
                         <p>
                             <label>Password</label> <br/>
                             <input class="password" type="password" value="" name="password"/>
                         </p>
                         <p>
                             <label>Repeat Password</label> <br/>
                             <input class="password" type="password" value="" name="password2"/>
                         </p>
                          <p>
                              <input type="submit" class="button gray small" value="Register" name="register" />
                          </p>
                      </fieldset>
                    </form>

            </div>
        </div>

<?include('footer.php');?>