MVC Controller Class

Here is my controller class for my MVC pattern with all the includes removed. From what I know of the MVC pattern it is good to have a small controller class. Mine is just a collection of public static functions which accept requests and send data to the client.

Regarding send(). I'm just wrapping the echo command for sending text from an Ajax call. This is for consistency and to have all text exiting the same point in code.

I have a ControlEntry (Snippet 2) which help decouple Super Globals and direct entry into the Control, so the two kind of work in Tandem.

Pull_Pic just pulls a path and inserts it into HTML for display.

Snippet 1

<?php

    class Control
    {
        public static function ajax($ajax_type)
        {
            Session::start();
            switch($ajax_type) 
            {
                case 'ControlBookmark_add': 
                    $control_bookmark_instance = new ControlBookmark('remove');
                    $control_bookmark_instance->add();
                    break; 
                case 'ControlBookmark_delete': 
                    $control_bookmark_instance = new ControlBookmark('remove');
                    $control_bookmark_instance->delete();
                    break; 
                case 'ControlTweet_add': 
                    $control_tweet_instance = new ControlTweet('remove');
                    $control_tweet_instance->add();
                    break; 
                case 'ControlSignIn':
                    $control_signin_instance = new ControlSignIn('remove');
                    $control_signin_instance->invoke();
                    break; 
                case 'ControlSignUp':
                    new ControlSignUp();
                    break;
                case 'ControlTryIt':
                    new ControlTryIt();
                    break; 
                case 'ControlSignOut': 
                    Session::finish();
                    new ControlSignOut();
                    break;
                default:
                    throw new Exception('Invalid ajax_type');
            }
        }
        public static function reload() // Because reload may be triggered by File Upload (second control path)
        {
            if (session_id() == "")
            {
                Session::start();
            }
            if((Session::status())==='bookmarks')
            {
                include 'class.ViewBookmarks.php';
            }
            else
            {
                include 'class.ViewMain.php';
            }
        }
        public static function upload($fileType, $fileName)
        {
            Session::start();
            $fileInstance = new UploadedFile($fileType, $fileName);
            $fileInstance->createImages();
            Session::updatePic();
            self::reload();
        }
        public static function send($textStream)
        {
            echo $textStream;
        }
    }

**Snippet 2**

    new ControlEntry();

    class ControlEntry
    {
        public function __construct()  
        {        
            if(isset( $_FILES['ufile']['tmp_name']) )
            {
                if( ( $_FILES['ufile']['tmp_name']) != '' )
                    {
                    Control::upload( $_FILES['ufile']['type'], $_FILES['ufile']['tmp_name'] );
                    }
                else
                    {
                    Control::reload();
                    }
            }
            else if( isset($_POST['ajax_type']) )
            {
                Control::ajax( $_POST['ajax_type'] );
            }
            else
            {
                Control::reload();
            }
        }
    }