Plugin admin page stylesheet doesn't work

Plugin admin page stylesheet doesn't work

I am trying to style my plugin's admin page. Below is the code is use, but
neither the stylesheet nor the script shows up on my page.
add_action( 'admin_init', 'myplugin_admin_init' );
add_action( 'admin_menu', 'myplugin_custom_menu_page' );
function myplugin_custom_menu_page(){
$page = add_menu_page( 'My Plugin', 'My Plugin', 'manage_options',
'myplugin/myplugin-admin.php', '', plugins_url(
'myplugin/images/icon.png' ), 33 );
add_action( 'admin_enqueue_scripts' . $page, 'myplugin_admin_styles' );
add_action( 'admin_enqueue_scripts' . $page, 'myplugin_admin_scripts' );
}
function myplugin_admin_init() {
wp_register_script( 'myplugin-script', plugins_url(
'myplugin/script.js') );
wp_register_style( 'myplugin-style',
plugins_url('myplugin/stylesheet.css') );
}
function myplugin_admin_styles() {
wp_enqueue_style( 'myplugin-style' );
}
function myplugin_admin_scripts() {
wp_enqueue_script( 'myplugin-script' );
}
Any hints would be much appreciated!