gistfile1.txt

  def create
    @user = current_user
    event = Event.find(params[:event_id])
    if @user.events.find_by_id(event)
      redirect_to event, notice: 'You can\'t enroll to the same event twice. Duh.'
      return
    else  
      @enrollment = @user.enrollments.build(event: event)
    end
    
    respond_to do |format|
      if @enrollment.save
        format.html { redirect_to @user, notice: 'Successfully enrolled' }
        format.json { render json: @user, status: :created, location: @user }
      else
        format.html { render action: "new" }
        format.json { render json: @enrollment.errors, status: :unprocessable_entity }
      end
    end
  end