PHP登录脚本不能在IE8或IE9中工作

我有一个使用PHP脚本登录用户的网站。它在大多数浏览器中运行良好，但IE8和IE9似乎在cookie上有问题。我读了一堆类似的帖子，但到目前为止似乎没有任何帮助。你知道问题出在哪里吗?详细代码如下:

我们在登录脚本中使用以下代码:http://www.wikihow.com/Create-a-Secure-Login-Script-in-PHP-and-MySQL

登录表单

 <?php
    if($error == 1) echo "<p class='"error'">Your Log in information is incorrect</p>";
    ?>
    <form class="form-horizontal" role="form" action="includes/process_login.php" method="post" name="login_form">
     <div class="form-group">
      <!-- <label for="inputEmail1" class="col-md-2 control-label">Email</label> -->
        <div class="col-md-12">
          <input type="email" class="form-control" id="inputEmail1" name="inputEmail1">
           </div>
           </div>
        <div class="form-group">
            <!-- <label for="inputPass1" class="col-md-2 control-label">Password</label> -->
             <div class="col-md-12">
             <input type="password" class="form-control" id="inputPass1" name="inputPass1">
              </div>
              </div>
        </div>
    </div>
    </div>
    </div>
    <div id="login-content">
           <div class="form-group">
              <button type="submit" class="btn btn-default signin-btn" onclick="formhash(this.form, this.form.inputPass1);">Sign In</button>
             </div>
              </form>

进程登录页面

<?php
header('P3P: CP="NOI ADM DEV COM NAV OUR STP"');
include_once 'db_connect.php';
include_once 'functions.php';
sec_session_start(); // Our custom secure way of starting a PHP session.

if (isset($_POST['inputEmail1'], $_POST['p'])) {
    $email = $_POST['inputEmail1'];
    $password = $_POST['p']; // The hashed password.
    exit($email);
    if (login($email, $password, $mysqli) == true) {
        // Login success 
        header('Location: ../index.php');
    } else {
        // Login failed 
        header('Location: ../index.php?error=1');
    }
} else {
    // The correct POST variables were not sent to this page. 
    echo 'Invalid Request';

}

//checks login info against db
function login($email, $password, $mysqli) {
    // Using prepared statements means that SQL injection is not possible. 
    if ($stmt = $mysqli->prepare("SELECT id, fname, lname, pass, salt, type_id 
        FROM users
       WHERE email = ?
        LIMIT 1")) {
        $stmt->bind_param('s', $email);  // Bind "$email" to parameter.
        $stmt->execute();    // Execute the prepared query.
        $stmt->store_result();
        // get variables from result.
        $stmt->bind_result($user_id, $fname, $lname, $db_password, $salt, $user_type);
        $stmt->fetch();
        // hash the password with the unique salt.
        $password = hash('sha512', $password . $salt);
        if ($stmt->num_rows == 1) {
            // If the user exists we check if the account is locked
            // from too many login attempts 
            if (checkbrute($user_id, $mysqli) == true) {
                // Account is locked 
                // Send an email to user saying their account is locked
                return false;
            } else {
                // Check if the password in the database matches
                // the password the user submitted.
                if ($db_password == $password) {                
                    // Password is correct!
                    // Get the user-agent string of the user.
                    $user_browser = $_SERVER['HTTP_USER_AGENT'];
                    // XSS protection as we might print this value
                    $user_id = preg_replace("/[^0-9]+/", "", $user_id);
                    $user_type = preg_replace("/[^0-9]+/", "", $user_type);
                    $_SESSION['user_id'] = $user_id;
                    $_SESSION['user_type'] = $user_type;
                    // XSS protection as we might print this value
                    $username = preg_replace("/[^a-zA-Z0-9_'-]+/", 
                                                                "", 
                                                                $fname . $lname);
                    $_SESSION['username'] = $username;
                    $_SESSION['login_string'] = hash('sha512', 
                              $password . $user_browser);
                    // Login successful.
                    return true;
                } else {
                    // Password is not correct
                    // We record this attempt in the database
                    $now = time();
                    $mysqli->query("INSERT INTO login_attempts(user_id, time)
                                    VALUES ('$user_id', '$now')");
                    return false;
                }
            }
        } else {
            // No user exists.
            return false;
        }
    }
}