Table Sorter plugin - fix wp_enqueue_scripts warning

--- table-sorter.orig.php   2015-05-01 13:41:41.000000000 +0100
+++ table-sorter.php    2015-05-01 23:24:18.008095400 +0100
@@ -9,10 +9,14 @@
  * License: Commercial
  */

-wp_register_script('table-sorter',plugins_url('table-sorter/jquery.tablesorter.min.js','table-sorter'),array('jquery'));
-wp_enqueue_script('table-sorter-metadata',plugins_url('table-sorter/jquery.metadata.js','table-sorter'),array('table-sorter'));
-wp_enqueue_script('table-sorter-custom-js',plugins_url('table-sorter/wp-script.js','table-sorter'));
-wp_enqueue_style('table-sorter-custom-css',plugins_url('table-sorter/wp-style.css'));
+
+function my_enqueue_scripts() {
+    wp_register_script('table-sorter',plugins_url('table-sorter/jquery.tablesorter.min.js','table-sorter'),array('jquery'));
+    wp_enqueue_script('table-sorter-metadata',plugins_url('table-sorter/jquery.metadata.js','table-sorter'),array('table-sorter'));
+    wp_enqueue_script('table-sorter-custom-js',plugins_url('table-sorter/wp-script.js','table-sorter'));
+    wp_enqueue_style('table-sorter-custom-css',plugins_url('table-sorter/wp-style.css'));
+}
+add_action( 'wp_enqueue_scripts', 'my_enqueue_scripts' );

 function my_plugin_menu(){
    add_options_page( 'Table Sorter', 'Table Sorter', 'manage_options', 'table-sorter', 'tablesorter_callback');