Missing Method in AboutController

You are seeing this error because the action sitemap.cfm is not defined in controller AboutController

Notice: this error is being rendered by the app/views/errors/missing_action.thtml view file, a user-customizable error page for handling invalid action dispatches.

Fatal: Create Method:

<?php
    class AboutController extends AppController
    {
        function sitemap.cfm()
        {

        }
    }
?>

in file : app/controllers/about_controller.php

Error: Unable to execute action sitemap.cfm in AboutController