<?php

//init
$_POST['username'] = $username;
$_POST['password'] = $password;
$_POST['submit'] = $submit;

// check

if ($submit)
{
    connect();
    if ($username && $password)
    {
        $sql = "SELECT username,password FROM users WHERE username = $username";
       $res = mysql_query($sql);
       if (mysql_num_rows($res) > 0)
       {
        $sql2 = "SELECT id FROM users WHERE username = $username AND password = sha1($password)";
        $res2 = mysql_query($sql2);
                    if(mysql_num_rows($res2) > 0)
                    {
                        $row = mysql_fetch_assoc($res2);
                        $_SESSION['uid'] = $row['id'];
                        echo "You have successfully logged in, $username .<br><br><a href=\"./index.php\">Click here to go to the forums.</a>";
                    }
                    else
                    {
                        die ("Username and password combination are incorrect!");
                    }
        }
        else
        {
            die("User does not exist!");
        }
    }
       else
        {
        die("Please fill in all fields!");
        }
}

?>