title: How can I update a list in mailchimp api version 3 using php in codeigniter?
body: <p>I have an existing list in mailchimp. I have cron in my helpers for generating a array list of users every 6 hours. Now I want to send the new email id's from this array to the old list so that just the new email ids' information  will be added to it. How can I do this. I have added mcapi.php in my libraries folder. and I am getting an array named user[]. so how should i call the api and listupdate method ? My mailchimp version is 3.0 and I am using codeigniter framework.</p>