I am new to using cake and am having difficulty at one of the first hurdles of my first application (outside of all the tutorials I've done!)

I have three models:
Property
Dealers
Photos

Dealers have many properties, properties have many photos.

Through reusing code from a tutorial, when adding a property, I can get a dropdown of all the dealers. The code looks something like this:

PHP Code:
<?php
class PropertiesController extends AppController {

    var 
$name 'Properties';
    var 
$helpers = array('Html''Form' );

    function 
index() {
        ...
    }

    function 
add() {
        if (empty(
$this->data)) {
            
$this->set('dealers'$this->Property->Dealer->generateList());
            
$this->render();
        } else {
            
// create property
            
}
        }
    }
However, when I try and reuse similar code in the Photos controller, such as this:
PHP Code:
<?php

class PhotosController extends AppController {
    var 
$name 'Photos';
    var 
$helpers = array('Html''Form' );
    
    function 
add()
    {
        if (empty(
$this->data)) {
        
$this->set('properties'$this->Property->Property->generateList());
        
$this->render();
        }
        else
        {
            
// add photo
        
}
    }
    
}
?>
I get horrific errors like this:
Code:
Notice: Undefined property: PhotosController::$Property in /Applications/MAMP/htdocs/property_inv/app/controllers/photos_controller.php on line 9

Notice: Trying to get property of non-object in /Applications/MAMP/htdocs/property_inv/app/controllers/photos_controller.php on line 9

Fatal error: Call to a member function generateList() on a non-object in /Applications/MAMP/htdocs/property_inv/app/controllers/photos_controller.php on line 9
Can anyone help me overcome this?

Many thanks!