Greater than and less than validation in Laravel 4

Just wrote some new validators for testing whether one attribute is greater than or less than another attribute in a Laravel 4 form. Here's the implementation, as well as how you can adjust the error messages.

Validator::extend('greater_than', function($attribute, $value, $parameters)
{
	$other = Input::get($parameters[0]);

    return isset($other) and intval($value) > intval($other);
});

Validator::extend('less_than', function($attribute, $value, $parameters)
{
    $other = Input::get($parameters[0]);

    return isset($other) and intval($value) < intval($other);
});

Now, you can set up your validations!

$validation = Validator::make(Input::all(), ['childs_birth_year' => 'greater_than:mothers_birth_year']);

Of course, if this validation fails, you're going to get an ugly error message (validation.greater_than to be specific). To override this, take a look in app/lang/en/validation.php and find the custom key.

'custom' = [
    'childs_birth_year' => [
        'greater_than' => "Your child must have been born after the mother."
    ]
]