rules: {
        email           :   {
            required        :   true,email           :   true,remote: {
                    url: SITE_URL + 'index.PHP?sign_up/emailValidate',type: "post",data: {
                      email: function() {
                        return $("#email").val();
                      }
                    }
                  }

        }

      },message:{
           email:   {
                required        :   "Email cant be empty.",email           :   "Please enter a valid email",remote          :   "This email already exists."

            }
      }