password protection access denied on certain files

I am trying to setup password protection to use with certain files. I have followed an online tutorial, and get some success but in other instances keep getting a call to a page denying access despite what appears to be the exact same operations being performed.

From my login page, the login script calls a php login page, which should store session ID. I then have a separate page that checks if the session ID has been stored, and that page (called auth.php) is included in the pages I am trying to protect. I put the php code at the very beginning of the file, and as I said for some test pages it works but for the pages I need it for it reverts to the access-denied page, which to me means it is not recognizing that the session ID has been stored. I'm not getting any error messages relating to connection issues, so my focus is on the session ID issue. Any thoughts would be appreciated.

Include code:

<?php
require_once('auth.php');
?>

auth.php code:

<?php
//Check whether the session variable SESS_MEMBER_ID is present or not
if(!isset($_SESSION['SESS_MEMBER_ID']) || (trim($_SESSION['SESS_MEMBER_ID']) == '')) {
    header("location: access-denied.php");
    exit();
}
  ?>

Pertinent portion of login script code:

//Create query
$qry="SELECT * FROM members WHERE login='$login' AND password='".md5($_POST['password'])."'";
$result=mysql_query($qry);

//Check whether the query was successful or not
if($result) {
    if(mysql_num_rows($result) == 1) {
        //Login Successful
        session_regenerate_id();
        $member = mysql_fetch_assoc($result);
        $_SESSION['SESS_MEMBER_ID'] = $member['member_id'];
        $_SESSION['SESS_FIRST_NAME'] = $member['firstname'];
        $_SESSION['SESS_LAST_NAME'] = $member['lastname'];
        session_write_close();
        header("location: member-index.php");
        exit();
    }else {
        //Login failed
        header("location: login-failed.php");
        exit();
    }
}else {
    die("Query failed");
}

Full login code:

<?php
//Start session
session_start();

//Include database connection details
require_once('config.php');

//Array to store validation errors
$errmsg_arr = array();

//Validation error flag
$errflag = false;


开发者_如何转开发//Function to sanitize values received from the form. Prevents SQL injection
function clean($str) {
    $str = @trim($str);
    if(get_magic_quotes_gpc()) {
        $str = stripslashes($str);
    }
    return mysql_real_escape_string($str);
}

//Sanitize the POST values
$login = clean($_POST['login']);
$password = clean($_POST['password']);

//Input Validations
if($login == '') {
    $errmsg_arr[] = 'Login ID missing';
    $errflag = true;
}
if($password == '') {
    $errmsg_arr[] = 'Password missing';
    $errflag = true;
}

//If there are input validations, redirect back to the login form
if($errflag) {
    $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
    session_write_close();
    header("location: login-form.php");
    exit();
}

//Create query
$qry="SELECT * FROM members WHERE login='$login' AND password='".md5($_POST['password'])."'";
$result=mysql_query($qry);

//Check whether the query was successful or not
if($result) {
    if(mysql_num_rows($result) == 1) {
        //Login Successful
        session_regenerate_id();
        $member = mysql_fetch_assoc($result);
        $_SESSION['SESS_MEMBER_ID'] = $member['member_id'];
        $_SESSION['SESS_FIRST_NAME'] = $member['firstname'];
        $_SESSION['SESS_LAST_NAME'] = $member['lastname'];
        session_write_close();
        header("location: member-index.php");
        exit();
    }else {
        //Login failed
        header("location: login-failed.php");
        exit();
    }
}else {
    die("Query failed");
}

?>

I'm not seeing any session_start() You need it (see the manual ) in the beginning of any php file that uses sessions...