Login page

<?php
    session_start();
?>
<!DOCTYPE html>
<html>
 <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1"><link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
     <link rel="stylesheet" type="text/css" href="inv.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>

<body class="body_sign_in">

    <div class="container">
        <div class="row">
            <div class="col-xs-6 col-xs-offset-3">

                <div class="well" id="sign_in_form">

                    <h1>Please Sign In</h1>

                    <form action="#" method="post">
                        <div class="form-group">
                            <label for="username">Username:</label>
                            <input class="form-control" type="text" name="username">
                        </div>

                        <div class="form-group">
                            <label for="password">Password:</label>
                            <input class="form-control" type="text" name="password">
                        </div>

                        <button class="btn btn-success sign_in_btn" type="submit" name="submit">Sign In</button>

                    </form>


                </div>


            </div>
        </div>
    </div>


    <!-- PHP Section -->

    <?php

    try {

        $host = "localhost";
        $dbname = "inventory";
        $username = "root";
        $pwd = " ";

        $conn = new PDO("mysql:host=$host; dbname=$dbname", $username, $pwd);
        // set the PDO error mode to exception
        $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        // echo "Connected Successfully!";
    }
    catch (PDOException $e) {
        echo "Connection failed: " . $e->getMessage();
    }

    if (isset($_POST['submit'])) {

        $username = $_POST['username'];
        $password = $_POST['password'];

        //set Session username variable
        $_SESSION['username'] = $username;
         // echo "Session variable is set!";

        // Check if username field is set
        if (empty($username)) {
            echo "<div class='container'><div class='row'><div class='col-xs-6 col-xs-offset-3'>";
            echo "<h3>Oops! Username is empty.</h3>";
            echo "</div></div>";
            exit();
        }

        // Check if password field is set
        if (empty($password)) {
            echo "<div class='container'><div class='row'><div class='col-xs-6 col-xs-offset-3'>";
            echo "<h3>Oops! Password is empty.</h3>";
            echo "</div></div>";
            exit();
        }


        // Query database for matching username and password
        $sql = "SELECT * FROM login WHERE username = :username AND password = :password";
        $statement = $conn->prepare($sql);
        $statement->execute(array (':username' => $username,':password' => $password));
        $count = $statement->rowCount();

        if ($count == 0) {
            echo "<div class='container'><div class='row'><div class='col-xs-6 col-xs-offset-3'>";
            echo "<h3>Sorry! Username and/or password is invalid. Try again!</h3>";
            echo "</div></div>";
            exit();
        }
        else if ($count > 0) {
            header('location: http://localhost/Inventory/inv_home.php');
        }

    }


    ?>

    <!-- PHP Section -->


    </body>
</html>