proseslogin

<?php
    require_once("connect.php");
    ob_start();
    $username=$_GET['username'];
    $password=$_GET['password'];
    $query=mysql_query("select * from tuser where username='$username' and password='$password'");
    $row_user=mysql_fetch_assoc($query);
    if (($username!="")&&($password!=""))
    {
        if (($username==$row_user['username'])&&($password==$row_user['password']))
        {
            session_start();
            session_register('username');
            session_register('password');
            header("location:admin/index.php");

        }
        else
        {
            echo "<script>alert('password salah');location.href='index.php'</script>";
        }
    }
    else
    {
        echo"<script>alert('kosong coy');location.href='index.php'</script>";
    }
?>