Login Script Issues

[Titan85]

I created a login script that works fine, but for some reason the first time I try to login it simply shows the login page again. Then when I get to the control panel and click on a link it once again returns me to the login page. On the 3rd login it works fine. Here is the login page script:

<?php

$ip = $_SERVER['REMOTE_ADDR'];

if ($_POST['login']) {
    $user = $_POST['user'];
    $pass = md5($_POST['password']);
    
        $chk_user = mysql_query("SELECT * FROM `clients` WHERE username = '$user'") or die ('Error Getting User Data! <br />' .mysql_error());
        $u = mysql_fetch_array($chk_user);
        $chk = mysql_num_rows($chk_user);
        
            if ($chk < 1) {
                echo '<meta http-equiv="refresh" content="2;URL=../login.php" />
                    The user <b>'.$user.'</b> does not exist!';
            } 
            elseif ($pass !== $u['password']) {
                echo '<meta http-equiv="refresh" content="2;URL=../login.php" />
                    Incorrect password';
            }
            elseif($pass == $u['password']) {        
            
                $user = $_POST['user'];
                $pass = md5($_POST['password']);
                    @session_start();
                        $_SESSION['user'] = $user;
                        $_SESSION['pass'] = $pass;
                        $_SESSION['ip'] = $_SERVER['REMOTE_ADDR'];
                    
                    echo '<meta http-equiv="refresh" content="2;URL=/beta/client_cp" />
                        '.$user.', you are now logged in, redirecting you to the main page...';
            }
}

elseif (!$_POST['login']) {
    ?>
        <div id="login"><b>Please Log In</b>
<!-- Login Form -->
        <form name="login" method="post" action="">
            <table width="230" align="center">
                <tr>
                    <td><b>Username:</b></td>
                    <td><input type="text" name="user" class="input" /></td>
                </tr>
                <tr>
                    <td><b>Password:</b></td>
                    <td><input type="password" name="password" class="input" /></td>
                </tr>
                <tr>
                    <td colspan="2" align="right"><input type="submit" name="login" value="Login" /></td>
                </tr>
            </table>
        </form>
<!-- /Login Form -->
        </div>
    <?
}

?>

This is how I check if logged in:

@session_start();
    if(empty($_SESSION['user']) || empty($_SESSION['pass']) || $_SESSION['ip'] != $_SERVER['REMOTE_ADDR']) {
    header('Location: ../login.php');
} 

Is there any obvious reason for this issue? Thanks for the help

[thetestingsite]

Try placing session_start() at the very beginning of the code (directly underneath the opening php tag). Also, when you do this, don't forget to take out the line @session_start().

Hope this helps.

[Titan85]

Try placing session_start() at the very beginning of the code (directly underneath the opening php tag). Also, when you do this, don't forget to take out the line @session_start().

Hope this helps.

EDIT
still having issues, see below.

[Titan85]

Actually, now it has the same problem again. I moved the session_start() and it just makes it loop. It seems that it never sets the session variables. Any ideas? Thanks