I have a form with 2 submit buttons;

<form class="form-horizontal" role="form" method="GET" action="{{ URL::to('split_form') }}">
{!! Form::hidden('postcode_id', $postcode_lookup['id']) !!}
<input class="btn btn-warning" type="submit" name="action" value="CSV" />
<input class="btn btn-info"    type="submit" name="action" value="Map"     />
</form>

Here is my routes.php;

Route::get('split_form', array(
    'before' => 'form_splitter',
    function()
    {
       print "three";
       Route::get('/export/csv', 'ExcelController@index');
       Route::get('/map/all', 'MapController@index');
    }
));

Here is my app/filters.php file;

<?php

Route::filter('form_splitter', function()
{
  if ( Input::get('action') === 'CSV' )
  {
    Redirect::to('/export/csv');
    print "one";
  }
  elseif ( Input::get('action') === 'Map' )
  {
    Redirect::to('/map/all');
    print "two";
  }
});

I'm doing just a couple of "hello worlds" on the two controllers at the moment but all I get back from the browser is "three". Do I have to register filters.php somewhere?