session2.php

if ( empty( $username ) ) {
    throw new RedirectException( 'index.php?empty_user=yes&resource=session&method=create' );
}
if ( empty( $password ) ) {
    throw new RedirectException( 'index.php?empty_pass=yes&resource=session&method=create'
}
$id = User::authenticateUser( $username, $password );
if ( $id == false ) {
    throw new RedirectException( 'index.php?resource=session&method=create&error=yes' );
}
$_SESSION[ 'user' ] = array(
    'userid' => $id,
    'username' => $username
);
throw new RedirectException( 'index.php?resource=dashboard&method=view' );