Calling a HTTP POST using Worklight REST adapter

I am trying to build Contact Management application using WorkLight that uses REST service as back end. You can take a look and download the REST service from Returning JSON response from JAXRS service This is how the insertContact() method of my JAXRS service looks like, the insertContact() method consumes MediaType.APPLICATION_FORM_URLENCODED

@POST
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
@Produces({MediaType.APPLICATION_JSON,MediaType.APPLICATION_XML})
public void insertContact(@FormParam("contactId") int contactId,
      @FormParam("firstName") String firstName,
      @FormParam("lastName") String lastName,
      @FormParam("email") String email) {
    Contact contact = new Contact();
    contact.setContactId(contactId);
    contact.setFirstName(firstName);
    contact.setLastName(lastName);
    contact.setEmail(email);
    ContactDAO contactDAO = new ContactDAOImpl();
    contactDAO.insertContact(contact);
}

This is how the insertContact() method in my REST adapter looks like. The method for this request is POST and the contentType is application/x-www-form-urlencoded i have to create the string representing the formBody and submit it in content.

function insertContact(firstName,lastName,email){
  WL.Logger.debug("Entering ContactRESTService1.insertContact()");
  var input = {
      method : 'post',
      returnedContentType : 'json',
      path : '/ManageContact/rest/contact',
      body:{
      contentType:'application/x-www-form-urlencoded',
      content:"firstName="+firstName+"&lastName="+lastName+"&email="+email
      } 
  };
  WL.Logger.debug("Exiting ContactRESTService1.insertContact()");
  return WL.Server.invokeHttp(input);
}