PHP Script for Admin login with session management & Logout

(1)first  write following code for Login form   "loginform.html"  file

<form action="login.php"  method="post">
<table border=0>
<tr><td>User name:</td>
<td>
                                         <input name="username" type="TEXT"></td> </tr>
                                  <tr><td>Password</td><td>
                                         <input name="Password" type="PASSWORD"></td>
                                         </tr>
                                       
                                   

                                    <tr>
                                        <td></td><td><input value="submit" name="SubmitUser" type="submit"></td>
</form>
                                    </tr>
                                </table>


(2) Then write code for  "login.php" file

<?php



$username=$_POST['username'];
$password=$_POST['password'];
$con=mysql_connect("hostname","username","password") or die(mysql_error());

mysql_select_db("databasename",$con);

$sql="select username,password  from login where username='$username'  AND password='$password'";

$result=mysql_query($sql) or die(mysql_error());

$num=mysql_num_rows($result) or die(mysql_error());


if($num>0)
{

 session_start();

 $_SESSION['username']=$username;

header("Location:dashboard.php");

}

else if($num==0)
{
header("Location:error.php");
}



?>


(3)Session management code:



<?php

session_start();
if(!isset($_SESSION['username']))
{

header("Location:index.php");

}


?>
NOte:
write this code on every your page starting or simply save it as

session.php  & on every page use it as

<?php  include("session.php");   ?>


(4)Logout code : save file name as "logout.php"

see below code:

<?php

session_start();

session_destroy();

header("Location:loginform.html");

?>