Load Javascript from Plugin in One Page Only?

Drop this in your functions.php or a custom plugin.

function wpse_57621_alo_tidy()
{
    if ( $page_id = get_option( 'alo_em_subsc_page' ) ) {
        if ( ! is_page( $page_id ) )
            remove_action( 'wp_head', 'alo_em_ajax_js' );
    }
}
add_action( 'wp', 'wpse_57621_alo_tidy' );

It’s attached to the wp hook, which runs just after the request has been handled & queried.

We’re saying “if the ALO newsletter page setting exists, but we’re not currently on said page, unattach the script output hook”.