CakePHP URL [Underscore to Hyphen]

I need some help about cakephp url underscore to hypen.

I've search already over the internet but cannot find the answer.

I followed the instruction in Cakephp(dot)org

http://book.cakephp.org/2.0/en/development/routing.html#passing-parameters-to-action

But still not working

What I wanted is to change the url

dashboard/view_profile to dashboard/view-profile

Controller : DashboardController

Action : view_profile

View : view_profile.ctp

Routes.php

Router::connect(
                'dashboard/:slug', 
                array('controller' => 'dashboard', 'action' => 'view_profile'),
                array('pass' => array('slug'))
                );

Link :

<?php echo $this->Html->link('View Profile', array('controller' => 'dashboard', 'action' => 'view_profile', 'slug' => 'view-profile')); ?>

Error :

 Error: The action view-profile is not defined in controller DashboardController

Error: Create DashboardController::view-profile() in file: app\Controller\DashboardController.php.

<?php
class DashboardController extends AppController {


    public function view-profile() {

    }

}