I'm new to PHP programming and have a simple program where I have an index page which accepts username and password. If user doesn't exist or wrong credentials are provided then I want to show index page again with error message. Here is what I have so far on my index.html:
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="Bella" >
    <title>Company Name - Log In</title>
    <!-- Bootstrap Core CSS -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- Custom CSS -->
    <link href="css/custom.css" rel="stylesheet">
    <!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
        <script src="https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js"></script>
        <script src="https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->
</head>
<body>
    <div id="fullscreen_bg" class="fullscreen_bg"/>
<div class="container">
    <form class="form-signin" action="loginAction.php" method="post">
        <h1 class="form-signin-heading text-muted">Log In</h1>
        <input type="text" name="email" class="form-control" placeholder="Email address" required="" autofocus="">
        <input type="password" name="password" class="form-control" placeholder="Password" required="">
        <button class="btn btn-lg btn-primary btn-block" type="submit">
            Log In
        </button>
    <a href="register.html" class="btn btn-md btn-warning btn-block">Register</a>       
    </form>
</div>
    <!-- /.container -->
    <!-- jQuery -->
    <script src="js/jquery.js"></script>
    <!-- Bootstrap Core JavaScript -->
    <script src="js/bootstrap.min.js"></script>
    <!-- Script to Activate the Carousel -->
    <script>
    $('.carousel').carousel({
        interval: 5000 //changes the speed
    })
    </script>
</body>
</html>
My LoginAction.php is:
<?php
ini_set('display_errors',1);
error_reporting(E_ALL);
//Set the Post results to variables
$email = $_POST("email");
$password = md5($_POST("password"));
//Get the database username, passwords, etc.
include('config.php');
// Create connection with the server
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
//Check for user
$sql = "SELECT * FROM users WHERE  email=" . $email . " AND password=" . $password . "";
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while($row = mysqli_fetch_assoc($result)) {
          mysqli_close($conn);
          session_start();
          $_SESSION['email'] = $row['email'];
          $_SESSION['id'] = $row['id'];
          $_SESSION['admin'] = true; //user is authenticated and the user is admin
          header"portal.php"; //redirect to another page
    }
} 
else {
    mysqli_close($conn);
    echo "<div class='alert alert-warning'>No User Found</div>";
    //header("Location: http://example.com/myOtherPage.php");
    //header"portal.php"; //redirect to another page
   include"index.html";
}
?>
It currently shows me blank LoginAction.php
 
     
     
     
    