WordPress - Contact 7 form - load js, css only needed pages

functions.php

<?php
/*
 Contact 7 form - load js, css only needed pages
 */

add_action( 'wp_print_scripts', 'deregister_cf7_javascript', 100 );
function deregister_cf7_javascript() {
    if ( !is_page(array(8, 10)) ) {
        wp_deregister_script( 'contact-form-7' );
    }
}
add_action( 'wp_print_styles', 'deregister_cf7_styles', 100 );
function deregister_cf7_styles() {
    if ( !is_page(array(8, 10)) ) {
        wp_deregister_style( 'contact-form-7' );
    }
}