PHP session with permissions - php

Question

I am having problem with the code.
It suppose to allow admin to view only admin page
and user to view user page only.
my admin still able to view user page.
below is my landing page
<?php
error_reporting(0);
include("config.php");
$host = "localhost"; //DB host
$username = "root"; //DB Username
$password = ""; //DB Password
$db_name = "hklcanet_pha"; //DB Name
$tbl_name = "users"; //Table name, where users are stored
$dbconfig = mysqli_connect($host,$username,$password,$db_name);
$username = $_POST['username']; //Get username from login form
$password = $_POST['password']; //Get password from login form
$username = stripslashes($username); //Makes string safe
$password = stripslashes($password); //Makes string safe
$username = mysqli_real_escape_string($dbconfig, $username); //Makes string safer
$password = mysqli_real_escape_string($dbconfig, $password); //Makes string safer
$sql = "SELECT * FROM $tbl_name WHERE username='$username' and password='$password'"; //SQL Query
$result = mysqli_query($dbconfig, $sql); //Executes Query
$rows = mysqli_num_rows($result); //Count rows selected (1 if a username/password combo can be found)
if($rows == 1){
session_start(); //Starts a PHP session
$_SESSION['username'] = $username; //Allows $username to be used later
header("location: interphase1.php");
$query = "SELECT * FROM $tbl_name WHERE username='$username' and password='$password'";
$result = mysqli_query($dbconfig, $query);
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC))
{
$permissions = $row['permissions']; //Gets the permissions of the user
$id = $row['id']; //Gets the ID of the user
}
$_SESSION['permissions'] = $permissions; //Allows $permissions to be used later
$_SESSION['id'] = $id; //Allows $id to be used later
$_SESSION['authenticated'] = 1; //Allows $id to be used later
echo("Login Succesful");//Prints success message
}
else
{
//echo("Invalid Username/Password");
}
?>
user page
<?php
session_start();
$permissions = $_SESSION['permissions'];
if($_SESSION['authenticated'] != 1)
{
echo("You must be logged in");
header("location:landing.php");
}
else
{
if($permissions < 0)
{
header("location:quicksummary.php");
echo("Your permissions are not high enough");
}
}
?>
admin page
<?php
session_start();
$permissions = $_SESSION['permissions'];
if($_SESSION['authenticated'] != 1)
{
header("location:landing.php");
echo("You must be logged in");
}
else
{
if($permissions < 1 )
{
header("location:quicksummary.php");
echo("Your permissions are not high enough");
}
}
?>
thanks and appreciate if somebody can help me on this, still new with the PHP code.