diff --git a/backend/lib/controller/channelcontroller.php b/backend/lib/controller/channelcontroller.php
index 12df55e..1638911 100644
--- a/backend/lib/controller/channelcontroller.php
+++ b/backend/lib/controller/channelcontroller.php
@@ -20,29 +20,8 @@
  */
 
 class ChannelController extends Controller {
-
-	public function __construct(View $view) {
-		parent::__construct($view);
-	}
-
-	public function execute() {
-		switch ($this->view->request->get['action']) {
-			case 'get':
-				$this->get();
-				break;
-				
-			case 'log':
-				$this->log();
-				break;
-				
-			default:
-				throw new InvalidArgumentException('Invalid action specified!');
-		}
-	}
-	
-	private function get() {
+	public function get() {
 		if ($this->view->request->get['data'] == 'channels' || $this->view->request->get['data'] == 'pulses') {
-			$this->view->type = 'channels';
 			$this->view->channels = array();
 				
 			if ($this->view->request->get['data'] == 'channels') {			// get all channels assigned to user
@@ -55,7 +34,7 @@ class ChannelController extends Controller {
 				
 				$from = (isset($this->view->request->get['from'])) ? (int) $this->view->request->get['from'] : NULL;
 				$to = (isset($this->view->request->get['to'])) ? (int) $this->view->request->get['to'] : NULL;
-				$groupBy = (isset($this->view->request->get['groupby'])) ? $this->view->request->get['groupby'] : 400;
+				$groupBy = (isset($this->view->request->get['groupby'])) ? $this->view->request->get['groupby'] : NULL;		// get all readings by default
 				
 				$this->view->from = $from;	// TODO use min max timestamps from Channel::getData()
 				$this->view->to = $to;
@@ -66,7 +45,6 @@ class ChannelController extends Controller {
 				$jsonChannel = $channel->toJson();		// TODO fix hardcoded json output
 
 				if ($this->view->request->get['data'] == 'pulses') {
-					$this->view->type = 'pulses';
 					$jsonChannel['pulses'] = array();
 					
 					foreach ($channel->getPulses($from, $to, $groupBy) as $pulse) {
@@ -81,7 +59,7 @@ class ChannelController extends Controller {
 		}
 	}
 	
-	private function log() {
+	public function log() {
 		$ucid = $this->view->request->get['ucid'];
 		
 		$channel = Channel::getByUcid($ucid);
diff --git a/backend/lib/controller/controller.php b/backend/lib/controller/controller.php
index 11ce546..c6c2606 100644
--- a/backend/lib/controller/controller.php
+++ b/backend/lib/controller/controller.php
@@ -19,14 +19,22 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
-abstract class Controller {
+class ControllerException extends Exception {};
+
+interface ControllerInterface {
+	public function __construct(View $view);
+}
+
+abstract class Controller implements ControllerInterface {
 	protected $view;
 	
 	public function __construct(View $view) {
 		$this->view = $view;
 	}
 	
-	abstract public function execute();
+	public function __call($method, $param) {
+		throw new ControllerException('Undefined controller action!');
+	}
 }
 
 ?>
\ No newline at end of file
diff --git a/backend/lib/controller/frontcontroller.php b/backend/lib/controller/frontcontroller.php
index 385678f..d5770fc 100644
--- a/backend/lib/controller/frontcontroller.php
+++ b/backend/lib/controller/frontcontroller.php
@@ -28,22 +28,23 @@ final class FrontController {
 		$response = new HttpResponse();
 		
 		// create view instance
-		$viewClass = new ReflectionClass($request->get['format'] . 'View');
-		if (!$viewClass->isSubclassOf('View')) {
-			throw new InvalidArgumentException('\'' . $viewClass->getName() . '\' is not a valid View');
+		$rc = new ReflectionClass($request->get['format'] . 'View');
+		if (!$rc->isSubclassOf('View')) {
+			throw new InvalidArgumentException('\'' . $rc->getName() . '\' is not a valid View');
 		}
-		$this->view = $viewClass->newInstanceArgs(array($request, $response));
+		$this->view = $rc->newInstanceArgs(array($request, $response));
 		
 		// create controller instance
-		$controllerClass = new ReflectionClass($request->get['controller'] . 'Controller');
-		if (!$controllerClass->isSubclassOf('Controller')) {
-			throw new InvalidArgumentException('\'' . $controllerClass->getName() . '\' is not a valid Controller');
+		$rc = new ReflectionClass($request->get['controller'] . 'Controller');
+		if (!$rc->isSubclassOf('Controller')) {
+			throw new InvalidArgumentException('\'' . $rc->getName() . '\' is not a valid Controller');
 		}
-		$this->controller = $controllerClass->newInstanceArgs(array($this->view));
+		$this->controller = $rc->newInstanceArgs(array($this->view));
 	}
 	
 	public function run() {
-		$this->controller->execute();	// run controller
+		$action = $this->view->request->get['action'];
+		$this->controller->$action();	// run controllers actions (usually CRUD: http://de.wikipedia.org/wiki/CRUD)
 		$this->view->render();			// send response
 	}
 }
diff --git a/backend/lib/controller/usercontroller.php b/backend/lib/controller/usercontroller.php
new file mode 100644
index 0000000..419c2fd
--- /dev/null
+++ b/backend/lib/controller/usercontroller.php
@@ -0,0 +1,42 @@
+<?php
+/*
+ * Copyright (c) 2010 by Justin Otherguy <justin@justinotherguy.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License (either version 2 or
+ * version 3) as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * For more information on the GPL, please go to:
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+class UserController extends Controller {
+	public function add() {
+		
+	}
+	
+	public function delete() {
+		
+	}
+	
+	public function edit() {
+		
+	}
+	
+	public function login() {
+		
+	}
+	
+	public function logout() {
+		
+	}
+}
\ No newline at end of file