The way to get to the old input is
Input::old('lat');
Here is the framework documentation about this http://laravel.com/docs/requests#old-input
However Laravel gives you a very simple way to deal with validation. Generally this is what the code in your controller should look like in Laravel 4.2. This would go in the controller method where your form is being submitted.
$rules = []; //specify your validation rules here
$validator = Validator::make(Input::all(), $rules);
if ($validator->fails())
{
return Redirect::to('register')->withInput()->withErrors($validator);
}
in your view you can get to the errors by using either
{{ $errors->first('email') }} // get error for the email field
or to get all the errors in the form
@foreach ($messages->all('<li>:message</li>') as $message)
{{ $message }}
@endforeach
Link to validation documentation: http://laravel.com/docs/validation
This is the simplest way to do this. Once you are a little more comfortable with the framework you can use Laracasts/Validation package.
In Laravel 5 the validation is done differently using the FormRequest object. Here is a link to the video https://laracasts.com/series/whats-new-in-laravel-5/episodes/3