Laravel 4中AJAX的Access Controller功能

I am new to Laravel, even I am new to PHP. I am trying to access a controller function through AJAX, which will return some data. Every time when I run AJAX it shows 404 error. I am not sure what am I doing wrong. Following is my code:

routes.php(now)

Route::get('/about' , 'HomeController@gtn');
Route::get('test' , array('as' => 'test', 'uses' => 'HomeController@test'));

Controller(HomeController.php) has these functions:

 public function test()
   {
        return 'Testing dude!!';
   }
    public function gets()
    {
        $data['stt'] = Mein::getstate();
        return View::make('/about',$data);
    }
    public function gtn()
    {           
        $data['shw'] = Mein::getCity();
        return View::make('/about',$data);
    }

My AJAX call(now):

 $.ajax({
    url:'{{route("about")}}',
    type:'GET',
    // data:'soni'
  });

I want to access test function of HomeController. I checked the call from browser, it shows 404.

You don't call a controller directly (and definitely not like that!), but you call a url, or better a route (Laravel has named routes, it's good to use them):

$.ajax({
 url:'{{route("about")}}',  // or url: '{{url("about")}}'
 type:'GET',
 success: function(rxp){
   // handle response here
   // es. $('#mydiv').html(rxp);
  }
});


Route::get('about' , array('as' => 'about', 'uses' => 'HomeController@gtn'));

Edit:

I want to access test function of HomeController

Then create a route for the test() method:

Route::get('test' , array('as' => 'test', 'uses' => 'HomeController@test'));

Update after comment:

I gave you blade syntax guessing you where using it in your template files. If you want to use blade, rename the file to filename.blade.php. Or else use php:

 url:'<?php echo route("about");?>',

var redirect_url = 'about';
        $.ajax({
    type: 'GET',
    url: 'about',
    data: { 'facilityid' : y , 'status' : val }
}).done(function () {
    window.location.href = redirect_url;
});

Route::get('about' , array('as' => 'about', 'uses' => 'HomeController@gtn'));