Untitled

<?php
 session_start();//session starts here
 ?>

  <?php
  error_reporting(E_ALL);
  ini_set("display_errors", 1);

  include("connection.php");

  if(isset($_POST['submit']))
  {
  $Mobile=$_POST['Mobile'];
  $Password=$_POST['Password'];

  $check_user="select * from
  UserRegLogs WHERE Mobile='$Mobile' AND Password='$Password'";

 $run=mysqli_query($dbcon,$check_user);

 if(mysqli_num_rows($run))
 {
echo "<script>window.open('mypage.php','_self'). </script>";

$_SESSION['Mobile']=$Mobile;//here session is used and value of $Mobile store in $_SESSION.

 }
 else
 {
   echo "<script>alert('Email or password is incorrect!').
     </script>";
  }
  }
  ?>

<?php
session_start();
if(!$_SESSION['Mobile'])
{

header("Location: login.php");//redirect to login page to secure the welcome page without login access.
}

?>

<html>
<head>
<title>Registration</title>
</head>

<body>
<h1>Welcome</h1><br>
<?php
echo $_SESSION['Mobile'];
?>


<h1><a href="logout.php">Logout here</a> </h1>