Laravel 3 vs 4

//Laravel 3 Site Model i can do somethink like that:
public function adformats()  {
    return $this->has_many_and_belongs_to('Adformat','sites_adformats')->with('zone_id');
}

In my Laravel 3 Controller i can do somethink like that:
$site->adformats()->pivot()->where('site_id','=',$site->id)->where('adformat_id','=',$adformatid)->update(array('zone_id' => $zoneid));

What do I need to do in Laravel 4?
In My Model i do this:
public function adformats()  {
    return $this->belongsToMany('Adformat','sites_adformats')->withPivot('zone_id');
}
Is that right?

How can access it now in Controller in Laravel 4?