How to include jQuery when writing a Plugin admin page

Hello,
I have been going crazy trying to figure out why my jQuery code is not working. I am writing a plugin and I want to use jQuery effects on the admin page. Here is what I have:

<?php  

/*
Plugin Name: jquerytest
Plugin URI:
Description: Meanwhile Media - jquerytest
Version: 1.0
Author: Me
Author URI:
License: GPL2
*/

add_action('admin_menu', 'jquerytest');
wp_enqueue_script('jquery');

function jquerytest() {
	add_menu_page('jquerytest', 'jquerytest', 'read', 'jquerytest', 'jquerytest_contents');
}

function jquerytest_contents() { ?>

    <input type="submit" name="togglepayout" value="Toggle" id="togglepayout" />
	<div name="payout" id="payout" style="margin: 5px 0 0 10px;">
    Test Text Test Text etc. etc.
    </div> 

	<script language="javascript">

		jquery(document).ready(function() {
			jquery('payout').hide();

			jquery('#togglepayout').click( function() {
    			jquery('payout').toggle();
   			});

		});

	</script> 

<?php } ?>

Can anyone help me?
Thanks!