asp.net - call a webservice with list<int> as paramter from jquery .ajax -

i have webservice webmethod looks like:

[webmethod(description = "gets places category & city")] [scriptmethod(responseformat = responseformat.json)]  public list<p> getcitiesps(int categoryid,list<int> cityids) {    return mymanager.getps(categoryid, cityids); } 

the parameter cityids list of values of checked checkboxes.

 var cityids = new array();  $('.city-checkbox').each(function() {             checked = $(this).attr('checked');             if (checked == true) {                 cityid = $(this).attr('value');                 cityids.push(cityid);             }          }); 

now when call webservice method .ajax,but doesn't fire.

var params = json.stringify({ 'categoryid': categoryid, 'cityids': cityids });     alert(params);      $.ajax({         type: "post",         url: "finkaynwebservice.asmx/getcitiesps",         data: parameters,         contenttype: "application/json; charset=utf-8",         datatype: "json",         success: function(response) {         },         failure: function(msg) {             alert('somethin went wrong' + msg);         }     }); 

why dont use $.post function instead

$.post(url-to-post-to, { data-to-post }, function() {     // callback code }, 'json'); 

http://api.jquery.com/jquery.post/