Whenever you want to send a form as ajax, include this small snipet of code for that...

form_to_ajax.js

// Receives the selector of a form and return the params as an array
// Example: 
// ["date=2013-01-11", "transactions[][transaction_type]=withdrawal", "transactions[][ammount]=", "transactions[][description]="]
function formAsParams(formSelector){
  var array = $(formSelector).serializeArray(),
  params = _.reduce(array, function(memo, elem){ memo.push(elem.name + "=" + elem.value); return memo; }, []);
  return params;
}

// Given a form with data-attributes data-post-to and data-method, it will do an ajax request to the url
// given in data-post-to using the html method provided in data-method.
// 
// This function is useful when you want to submit a form (without files) as an ajax request using jquery AJAX.
// 
// Example call:
// 
//   formToJson({
//     formSelector: '#my-form-id',
//     successCallback: function(){console.log('Success')}, 
//     beforeCallback: function(){console.log('before')}, 
//     errorCallback: function(){console.log('error')}, 
//     completeCallback: function(){console.log('completed')}
//   });
function formToJson(attributes){
  var 
    options = $.extend({formSelector: null, successCallback: null, beforeCallback: null, errorCallback:null, completeCallback: null}, attributes),
    form = $(options.formSelector),
    ajaxPath = form.attr('data-post-to'),
    method = form.attr('data-method');

  form.on('submit', function(evt){
    evt.stopPropagation();
    evt.preventDefault();

    $.ajax(ajaxPath, {
      dataType: 'json',
      type: method,
      data: formAsParams(options.formSelector).join("&"),
      beforeSend: function(data){
        if(options.beforeCallback) {
          options.beforeCallback(data);
        }
      },
      success: function(data){
        if(options.successCallback) {
          options.successCallback(data);
        }
      },
      error: function(data){
        if(options.errorCallback) {
          options.errorCallback(data);
        }
      },
      complete: function(data){
        if(options.completeCallback) {
          options.completeCallback(data);
        }
      }
    });
  });
}