php login redirect

[grizli]

Hi! I have some some sections in my site and I use a header for each of them. In my header file I have the next code:

<?php
session_start();
?>

<div id="kazan">
        <div id="gore">
            <?php
                if(empty($_SESSION['username']))
                {
                require('login/reg_data.php');
                }
                
            ?>
                <div id="begin"><a href="index.php">Начало</a></div>

        </div>

            <div id="flash">

                <div>    

            <object id="myId" classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" width="576" height="116">

                <param name="movie" value="cat_and_mouse.swf" />

                <!--[if !IE]>-->

                <object type="application/x-shockwave-flash" data="cat_and_mouse.swf" width="576" height="116">

                <!--<![endif]-->

                <div>
                <h1>flash movie clip</h1>
                <p><a href="http://www.adobe.com/go/getflashplayer"><img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" /></a></p>
                </div>
                <!--[if !IE]>-->
                </object>
                <!--<![endif]-->
            </object>
                </div>
            
            </div>
            
            <div id="goreright">
    <?php 
        if(!empty($_SESSION['username'])) 
        { 
        echo '<div id="lognat"><ul><li></li>Здравей,<li><a href="login/members.php">'.$_SESSION['username'].'</a></li></ul>
        <p><a href="login/logout.php">Изход</a></p></div>';
        }
        else if(isset($_SESSION['error'])){
        echo '<div class="mistake">';
        echo $_SESSION['error'];
        echo '</div>';
        session_destroy() ;
        
        echo '<form method="POST" action="login/login.php" class="login">';
        echo '<label for="name">Име</label><br>';
        echo '<input type="text" name="username" size="15" maxlength="13" />';
        echo '<label for="password">Парола</label><br>';
        echo '<input type="password" name="password" size="15" maxlength="14" />';
        echo '<input type="submit" value="Влез" style="margin: 3px 0 0 0; font-size:11px;" />';
        echo '<input type="checkbox" name="autologin" value="1" checked="checked" />Помни';
        echo '</form>';
    }else{
        echo '<form method="POST" action="login/login.php" class="login">';
        echo '<label for="name">Име</label><br>';
        echo '<input type="text" name="username" size="15" maxlength="13" />';
        echo '<label for="password">Парола</label><br>';
        echo '<input type="password" name="password" size="15" maxlength="14" />';
        echo '<input type="submit" value="Влез" style="margin: 3px 0 0 0; font-size:11px;" />';
        echo '<input type="checkbox" name="autologin" value="1" checked="checked" />Помни';
        echo '</form>';
    }
?>
            </div>

Every section require this php file. And I have file: login.php:

 <?php
session_start();
require ("dbConfig.php");

$username = addslashes($_POST['username']);
$password = md5(addslashes($_POST['password']));

if($_SERVER['REQUEST_METHOD'] != 'POST') header('Location:../index.php');


if(isset($username) && isset($password)){
    $q = mysql_query("SELECT username, password FROM users WHERE username='$username' AND password='$password'LIMIT 1"); 
        
    if($row=mysql_fetch_array($q)){
        $_SESSION['username'] = $row['username'];
        header('Location:../index.php');        
    }else{
        $_SESSION['error'] = '<div class="mistake">Грешни данни</div>'; 
        header('Location:../index.php');
    }
    
}
?>

1 header file and 1 login file. The problem is that in this situation if i am in a section of my site after login I am redirected to index.php. This is uncomfortable for the visitors. I want after login the user to remain on the same pade, where he has been befor login. I can't write php code - only a little editing. Can someone help me with writing this code? Every help will be appreciated. Thank's in advance!