JQuery Initialization Plugin

Im trying to write a simple plugin that just initializes JQuery, JQuery UI and a few widgets.

<?php
	/*
	Plugin Name: Jquery Initialization
	*/

	function jquery_enqueuer() {
		global $wp_scripts;

		if(!wp_script_is('jquery')) wp_enqueue_script('jquery');
		if(!wp_script_is('jquery-ui-core')) {
			wp_enqueue_script('jquery-ui-core');
			$ui = $wp_scripts->query('jquery-ui-core');
			$url = "http://ajax.googleapis.com/ajax/libs/jqueryui/{$ui->ver}/themes/smoothness/jquery-ui.css";
			wp_enqueue_style('jquery-ui-smoothness', $url, false, $ui->ver);
		}
		if(!wp_script_is('jquery-ui-tabs')) wp_enqueue_script('jquery-ui-tabs');
		if(!wp_script_is('jquery-ui-datepicker')) wp_enqueue_script('jquery-ui-datepicker');
	}

	//action to run after wordpress finishes loading but before headers are sent
	add_action("init", "jquery_enqueuer");
?>

I used another simple page with a datepicker on it to test this. When I go to the page (sorry the page is localhost) nothing happens when I click on the datepicker. I right clicked and “Inspect Elements” and go to the “Network” tab. There I noticed that jquery.js loads but not jquery-ui or any of the other widgets. Can anyone give me some pointers on how to get them to load or any errors in the above plugin.Thanks in advance.