Selam arkadaşlar kullandığım oturum kontrolü sistemimde üyelere;
admin, editor, üye adında kullanıcı yetkileri vermek istiyorum araştırma yapmama rağmen beceremedim nasıl yapabiliriz ?

Admin giriş sayfamız
index.php

<?php
include("../config.php");
session_start(); ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
	<meta name="robots" content="noindex,nofollow,nosnippet,noodp,noarchive,noimageindex">	
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/reset.css" /> 
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/main.css" /> 
	<!--[if lte IE 6]><link rel="stylesheet" media="screen,projection" type="text/css" href="css/main-ie6.css" /><![endif]-->
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/style.css" /> 
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/mystyle.css" />
	<title>Yönetim Paneli</title>
</head>

<body>

<div id="main">

<div id="content" class="box" align="center">
	<br><br><br><br><br><br>
	<a href="index.php"><img src="design/logo.png" border="0" /></a>
	<br><br><br><br><br><br>
	<?php
	if(isset($_POST['gonder'])){
	$username = $_POST['username'];
	$password = $_POST['password'];

	$parola = md5($password);

	if($username==""||$password==""){

				echo '<p class="msg error" style="width:300px;"><b>Alanları boş geçemezsiniz!</b></p><br>'; }else{

	$query = mysql_query("SELECT * FROM administrator WHERE username='$username'");
	if(mysql_num_rows($query)=="0"){
			echo '<p class="msg error" style="width:300px;"><b>Girdiğiniz bilgiler hatalı!</b></p><br>'; }else{
	while ($row = mysql_fetch_assoc($query)){

	 $dbusername = $row['username'];
	 $dbpassword = $row['password'];
	 
	 if($username==$dbusername&&$parola==$dbpassword){

		$_SESSION['giris']="$username";
		echo '<p class="msg done" style="width:300px;"><b>Giriş yapıldı.</b></p><br>';
		echo '<script language="javascript">location.href="home.php";</script>'; 
		
	}else{

		echo '<p class="msg warning" style="width:300px;"><b>Kullanıcı Adı yada Şifre Hatalı!</b></p><br>';
		
	 } } } } } ?>
	 <form method="post">
						<dl>
							<dt><label for="email">Kullanıcı Adı</label></dt>
							<dd><input type="text" name="username" class="dsaciklama" /></dd>
						</dl>
						<dl>
							<dt><label for="password">Şifre</label></dt>
							<dd><input type="password" name="password" class="dsaciklama" /></dd>
						</dl>
						
						 <dl>
						<input type="submit" name="gonder" value="Giriş Yap" style="background: #E6E6E6; border: 1px solid #ccc; padding: 3px 7px; border-radius: 3px; color: #000; cursor:pointer" />
						 </dl>       
	</form>
		<br><br><br><br>
</div> 

</div> 

<hr class="noscreen" />

<div id="footer" class="box">
	<p class="f-left"><a href="http://www.site.com/" target="_blank">Site.com</a></p>
</div> 

</body>
</html>

Admin Görebidiği sayfa
hakkimizda.php


<?php 
session_start();
if(isset($_SESSION['giris'])){
$kuladi = $_SESSION['giris']; include("../config.php");
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
	<meta http-equiv="content-type" content="text/html; charset=utf-8" />
	<meta name="robots" content="noindex,nofollow,nosnippet,noodp,noarchive,noimageindex">
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/reset.css" /> 
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/main.css" /> 
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/2col.css" title="2col" /> 
	<link rel="alternate stylesheet" media="screen,projection" type="text/css" href="css/1col.css" title="1col" /> 
	<!--[if lte IE 6]><link rel="stylesheet" media="screen,projection" type="text/css" href="css/main-ie6.css" /><![endif]--> 
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/style.css" />
	<link rel="stylesheet" media="screen,projection" type="text/css" href="css/mystyle.css" />
	<script type="text/javascript" src="js/jquery.js"></script>
	<script type="text/javascript" src="js/switcher.js"></script>
	
		<script type="text/javascript" src="editor/nicEdit.js"></script>
		<script type="text/javascript">
		bkLib.onDomLoaded(function() { nicEditors.allTextAreas() });
		</script>
	<title>Yönetim Paneli</title>
</head>

<body>

<div id="main">

	<div id="tray" class="box">

		<p class="f-left box">

			<span class="f-left" id="switcher">
				<a href="#" rel="1col" class="styleswitch ico-col1" title="Display one column"><img src="design/switcher-1col.gif" alt="1 Column" /></a>
				<a href="#" rel="2col" class="styleswitch ico-col2" title="Display two columns"><img src="design/switcher-2col.gif" alt="2 Columns" /></a>
			</span>

			<strong>Yönetim Paneli</strong>

		</p>

		<p class="f-right"><strong><a href="admin.php"><?php echo $kuladi; ?></a></strong> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong><a href="logout.php" id="logout">Çıkış</a></strong></p>

	</div>

	<hr class="noscreen" />

	<div id="menu" class="box">

		<ul class="box f-right">
			<li><a href="../index.php" target="_blank"><span><strong>Siteyi Görüntüle &raquo;</strong></span></a></li>
		</ul>

		<ul class="box">
			<li><a href="home.php"><span>Yönetim Paneli Anasayfa</span></a></li>				
		</ul>

	</div>

	<hr class="noscreen" />

	<div id="cols" class="box">

		<div id="aside" class="box">
			<div class="padding box">
				<p id="logo"><a href="home.php"><img src="design/logo.png" title="Yönetim Paneli" alt="" /></a></p><br>
			</div>
			<div class="padding box"></div>
			<div class="padding box" class="info msg">
			<b>site</b><br>Yönetim Paneli<br><a href="http://www.site.com.tr" target="_blank">www.site.gen.tr</a>
			</div>
		</div>

		<hr class="noscreen" />

<div id="content" class="box">

	<h1>Hakkımızda</h1>		
	<?php

	$bul = mysql_query("select * from r_hakkimizda order by id desc");
	echo "
	<div id='kurumsal_icerik_genel'>";
	while ($goster = mysql_fetch_array($bul)){
	extract($goster);
	if($goster)
	echo "<div id='kurumsal_icerik'>";
	echo "<b>";
	echo stripslashes($goster['baslik'])."</b><br/><br/>";
	echo stripslashes($goster['mesaj'])."<br/>";
	echo "
		<br/><a href='hakkimizda_duzenle.php?id={$id}'>Bu Mesajı Düzenle</a><b>
		</div>";
	}

	?> 
				<br>
			</div>

</div>

	<hr class="noscreen" />

	<div id="footer" class="box">
		<p class="f-left"><a href="http://www.site.com/" target="_blank">Site.com</a></p>
	</div> 

</div>
</div>

</body>
</html>
<?php } else { echo '<script language="javascript">location.href="../404.html";</script>'; } ?>