I'm new to zend framework 2 and I have a question on comparing two inputs in the factory-backed form. My scenario is like following:

I want to compare two inputs, for example, `$startDate` and `$endDate`. I want to validate that `$startDate` is always less than `$endDate`. How I'm going to do this? For example:

```
$inputFilter->add($factory->createInput(array(
                'name'     => 'startDate',
                'required' => true,
                'validators' => array(
                    array(
                        'name'    => 'LessThan',
                        'options' => array(
                            'max'      => $endDate,
                        ),
                    ),
                ),
            )));

```

FYI, I'm following the Album tutorial and the `$inputFilter` is created in the `classTable.php`.

Thanks