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<?php
include('SqlConnect.php');
?>
<link rel="Stylesheet" type="text/css" href="style.css" />
<link href='http://fonts.googleapis.com/css?family=Karla:400,700,700italic,400italic' rel='stylesheet' type='text/css'>
<?php
if (isset($_POST['Login'])){
    if (!@mysql_connect($host, $username, $password)) die("Can't connect to database");
    if (!mysql_select_db($db_name)) die("Can't select database");
    $username=$_POST['username'];
    $password=$_POST['password'];
    $username = stripslashes($username);
    $password = stripslashes($password);
    $username = mysql_real_escape_string($username);
    $password = mysql_real_escape_string($password);
    $sql="SELECT * FROM $tbl_name WHERE username='$username' and password='$password'";
    $result=mysql_query($sql);
    $count=mysql_num_rows($result);
    if($count >= 1){
    $_SESSION['username']= "username";
    $_SESSION['password']= "password";
    header("location: index.php");
    echo "<center><font color='green'><b>Logged in Successfully</center></font></b>";
    } else {
        echo "<center><font color='red'><b>Wrong Username or Password</center></font></b>";
    }
}

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

ob_start();