loginform

<?php
session_start()
?>

<html>
    <head>
        <title>
            Login Form
        </title>

        <style>
            body {
                background-color: #c0c0c0;
                padding-top: 50px;
                padding-bottom: 50px;
                position: relative;
            }

            .container{

                border-radius: 5px;
                padding: 20px;
                text-align: center;
            }
             input[type=text] {
                box-shadow: 2px 2px #838789;
                opacity: 0.8;
                border-radius: 5px;
                width: 250px;
                height: 40px;
                border: 3px darkgrey;
                margin:auto;
                margin-bottom:  5px;
                display: inline-block;
                padding: 12px 20px;

            }

             input[type=password] {
                box-shadow: 2px 2px #838789;
                opacity: 0.8;
                border-radius: 5px;
                width: 250px;
                height: 40px;
                border: 3px darkgrey;
                margin:auto;
                margin-bottom: 20px;
                display: inline;
                padding: 12px 20px;


            }

            input[type=submit]:hover{


            }

            p{
                font-style: italic;
                font-family: Verdana;
                text-align: center;
            }

            form{
                margin: 0 auto;
                width:250px;

            }
        </style>


    </head>

    <body>
        <div>
            <?php

            $login = $_POST['login'];
            $username=$_POST['username'];
            $password=$_POST['password'];
        if(isset($login) && !empty($username) &&
                !empty($password))
        {

            if($username=='elena' && $password=='1234')
            { $_SESSION['valid']=true;
                echo 'You have entered a valid username and password';
            }
            else {
                echo 'Wrong username or password';
            }
        }

        ?>

        </div>

        <div class="container">
            <form action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']); ?>"
                  method="post"; accept-charset="UTF-8">
                <p> Username:</p>
                <input type="text" align="center" name="username" maxlength="50" autofocus> <br/>
                <p>Password: </p>
                <input type="password"  name="password" maxlength="50"><br/>
                <input type="submit"  name="login" value="Submit" formtarget="_blank">
            </form>

        </div>
    </body>
</html>