how to implement ajax in Code igniter

[eluser]NachoF[/eluser]
[quote author="Bramme" date="1240832645"]
This is my php code, plain and simple:

Code:

function get_html() {
        echo $this->mdl_gallery->get_gallery_html($this->input->post('id'));
    }

The function just calls a method that creates a bunch of html, based on the id. I simply echo that html, no need for views or so (but you could use them offcourse).[/quote]

Thats how I do it.. but I hate having to echo inside my controller... it doesnt seem to follow the whole purpose of MVC... how exactly would you do it if you wanted to use views?