PHP New

login.php

<form action="" method="post" name="Login_Form">
  <table width="400" border="0" align="center" cellpadding="5" cellspacing="1" class="Table">
    <?php if(isset($msg)){?>
    <tr>
      <td colspan="2" align="center" valign="top"><?php echo $msg;?></td>
    </tr>
    <?php } ?>
    <tr>
      <td colspan="2" align="left" valign="top"><h3>Login</h3></td>
    </tr>
    <tr>
      <td align="right" valign="top">Username</td>
      <td><input name="Username" type="text" class="Input"></td>
    </tr>
    <tr>
      <td align="right">Password</td>
      <td><input name="Password" type="password" class="Input"></td>
    </tr>
    <tr>
      <td> </td>
      <td><input name="Submit" type="submit" value="Login" class="Button3"></td>
    </tr>
  </table>
</form>

______________________________________________________
Step 2: Next we need to write a php script to check the
login authentication.


<?php session_start(); /* Starts the session */

/* Check Login form submitted */
if(isset($_POST['Submit'])){
/* Define username and associated password array */
$logins = array('Alex' => '123456','username1' => 'password1','username2' => 'password2');

/* Check and assign submitted Username and Password to new variable */
$Username = isset($_POST['Username']) ? $_POST['Username'] : '';
$Password = isset($_POST['Password']) ? $_POST['Password'] : '';

/* Check Username and Password existence in defined array */
if (isset($logins[$Username]) && $logins[$Username] == $Password){
/* Success: Set session variables and redirect to Protected page  */
$_SESSION['UserData']['Username']=$logins[$Username];
header("location:index.php");
exit;
} else {
/*Unsuccessful attempt: Set error message */
$msg="<span style='color:red'>Invalid Login Details</span>";
}
}
?>

____________________________________________________________

Step 3: If the login is correct then we need to redirect page to
 protected area.So need an protected script page too.

index.php

<?php session_start(); /* Starts the session */

if(!isset($_SESSION['UserData']['Username'])){
header("location:login.php");
exit;
}
?>
__________________________________________________________

index.php

<?php session_start(); /* Starts the session */

if(!isset($_SESSION['UserData']['Username'])){
header("location:login.php");
exit;
}
?>

Congratulation! You have logged into password protected page.
<a href="logout.php">Click here</a> to Logout.
__________________________________________________________

logout.php

<?php session_start(); /* Starts the session */
session_destroy(); /* Destroy started session */
header("location:login.php");  /* Redirect to login page */
exit;
?>
Congratulation! You have logged into password protected page. <a href="logout.php">Click here</a> to Logout.
Ready, now our login system perfectly done but we also need to provide a logout facility to user, so we require to create a logout page.

logout.php
Example:
<?php session_start(); /* Starts the session */
session_destroy(); /* Destroy started session */
header("location:login.php");  /* Redirect to login page */
exit;
?>