สอบถามเรื่องการกำหนดสิทธิ์เข้าใช้งานของ admin และ user หน่อยครับ

<?php
			if($_SESSION['level_id'] == "1")
				{
					include('left_menu/menu_lev_1.php');
				}
			else if($_SESSION['level_id'] == "2")
				{
					include('left_menu/menu_lev_2.php');
				}
			else if($_SESSION['level_id'] == "3")
				{
					include('left_menu/menu_lev_3.php');
				}
			else if($_SESSION['level_id'] == "4")
				{
					include('left_menu/menu_lev_4.php');
				}
			else if($_SESSION['level_id'] == "5")
				{
					include('left_menu/menu_lev_5.php');
				}
			else if($_SESSION['level_id'] == "6")
				{
					include('left_menu/menu_lev_6.php');
				}
			else if($_SESSION['level_id'] == "7")
				{
					include('left_menu/menu_lev_7.php');
				}
			else if($_SESSION['level_id'] == "8")
				{
					include('left_menu/menu_lev_8.php');
				}
			else if($_SESSION['level_id'] == "9")
				{
					include('left_menu/menu_lev_9.php');
				}
			else if($_SESSION['level_id'] == "10")
				{
					include('left_menu/menu_lev_10.php');
				}
		?>