<?php
$username = $_POST['username'];
$password = sha1($_POST['password']);

if($_SERVER['REQUEST_METHOD'] == 'POST')
{
    $connect = mysql_connect('localhost', 'root', '') or die ('Couldn\'t Connect');
    mysql_select_db("test") or die ("Couldn\'t Find your database !");
    
    $query = sprintf("SELECT id, username, password FROM users WHERE `username`='%s' AND `password`='%s'",
    mysql_real_escape_string($username),
    mysql_real_escape_string($password));
    

   $rows = mysql_query($query);

    $numrows = mysql_num_rows($rows); 


    if($numrows)
    {
        while($row = mysql_fetch_assoc($rows))
        {
            $dbusername = $row['username'];
            $dbpassword = $row['password'];
        }
        
            echo("<p>Welcome back ".$dbusername." !</p>");
            echo("<a href='logout.php'>Logout</a>");
            
        $_SESSION['username'] = $dbusername;
    }
    else
        die("Username or Password is wrong!");
        
}
?>

<?php
$username = $_POST['username'];
$password = sha1($_POST['password']);
 
if($_SERVER['REQUEST_METHOD'] == 'POST')
{
    $connect = mysql_connect('localhost', 'root', '') or die ('Couldn\'t Connect');
    mysql_select_db("test") or die ("Couldn\'t Find your database !");
 
    $query = sprintf("SELECT id, username, password FROM users WHERE `username`='%s' AND `password`='%s'",
    mysql_real_escape_string($username),
    mysql_real_escape_string($password));
 
 
   $rows = mysql_query($query);
 
    $numrows = mysql_num_rows($rows); 
 
 
    if($numrows)
    {
        while($row = mysql_fetch_assoc($rows))
        {
            $dbusername = $row['username'];
            $dbpassword = $row['password'];
        }
 
            echo("<p>Welcome back ".$dbusername." !</p>");
            echo("<a href='logout.php'>Logout</a>");
 
        $_SESSION['username'] = $dbusername;
    }
    else
        die("Username or Password is wrong!");
 
}
?>