Symfony jQuery Ajax请求

I'm new in symfony , and dont understand the way how to do ajax request . I read symfony chapter18 for ajax and some google result but I can't explain myself this info . I need translate myself how I can do someting like this in symfony

$(".but_addlap").live("click",function(){


                  $.ajax({
                             url: "laps_edit.php",
                             type: "POST",
                             data: "some data,
                             success: function(result1)
                             {

                                      put some  data from result into div 
                             }   

in procedure php I create php file to do some things , get answer and return answer into div . please help me to understand how to do this in Symfony . what I need to write in action, layout and others ..
I hope my english is not to bad to understand my post .

The piece of code you're showing us is javascript. It happens client-side, so there is no symfony involved here. The only thing that will probably change is the url, which will be more like this : /index.php/laps/edit