First, include jQuery in your page:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>

Here is the API 2 of cPanel:
http://docs.cpanel.net/twiki/bin/view/ApiDocs/Api2/WebHome
Find the modules and function names you need, and use them when calling the function below.
Copy the following function to your webpage:

function cpanel_call(module, fct, domain, user, password, secure, port, json, callback, return_as, async)
{
var protocol = secure ? "https" : "http";
var data_type = json [...]