To complete a simple Ajax call within the administration panels, we will need a minimum of three functions. Here are the functions used in the sample code:

• _wp_display_content() — responsible for displaying the form or content, and the nonce field.
• _wp_display_content_js() — displays the JavaScript code for our Ajax call in the footer.
• _wp_sample_ajax_call() — completes security check for the Ajax request, processes the request, and returns a response.

/**
 * How to make Ajax calls within the WP Administration Panels.
 *
 * @author Chris Strosser
 * @version 20090822
 */

// Define the $ajax_action (should be unique).
$ajax_action = 'wp_custom_ajax_call';

/**
 * Display nonce field and page/form content.
 *
 * @return void
 */
function _wp_display_content() {
	global $ajax_action;
	
	wp_create_nonce($ajax_action);
	
	// Put form content or content that requires an Ajax call here...
}

/**
 * This is the function that displays the JavaScript for the Ajax call.
 * JavaScript can also be stored in an external file, registered as a WP
 * script, and then enqueued for inclusion in the load-scripts.php file.
 *
 * @return void
 */
function _wp_display_content_js() {
	global $ajax_action, $nonce;
?>
<script type="text/javascript">
/* <![CDATA[ */

(function($) {
	$.ajax({
		type: "post",
		url: "admin-ajax.php",
		data: {
			action: '<?php echo esc_js( $ajax_action ); ?>',
			_ajax_nonce: '<?php echo esc_js( $nonce ); ?>'
		},
		beforeSend: function() {},
		complete: function() {},
		success: function(response) {}
	});
})(jQuery);

/* ]]> */
</script>
<?php
}
add_action('admin_print_footer_scripts', '_wp_display_content_js');

/**
 * This will be called by admin-ajax.php according to the action passed.
 *
 * The admin-ajax.php file will execute do_action('wp_ajax_<insert action here>') if
 * there aren't any preexisting calls with that name.
 */
function _wp_sample_ajax_call() {
	global $ajax_action;
	
	check_ajax_referer($ajax_action);
	
	// The data or content to return
	
	exit();
}
add_action('wp_ajax_' . $ajax_action, '_wp_sample_ajax_call');