title: How to pass formcollection using ajax call to an action?
body: <p>I'm trying to replace a form submit with ajax call. the action needs formcollection and I don't want to create a new Model. So I need to pass the whole form (just like form submit) but through ajax call. 
  I tried to serialize and using Json but the formcollection is empty. 
  this is my action signature:</p>
  
  <pre><code>public ActionResult CompleteRegisteration(FormCollection formCollection)
  </code></pre>
  
  <p>and here is my submit button click:</p>
  
  <pre><code>var form = $("#onlineform").serialize();              
              $.ajax({
                  url: "/Register/CompleteRegisteration",                
                  datatype: 'json',
                  data: JSON.stringify(form),
                  contentType: "application/json; charset=utf-8",                
                  success: function (data) {
                      if (data.result == "Error") {
                          alert(data.message);
                      }
                  }
              });
  </code></pre>
  
  <p>now how can I pass data into formcollection? </p>