ActiveRecord::RecordNotFound in AlbumsController#create

Couldn't find User without an ID

<%= form_for (@album), :remote => true, :html => { :id => "uploadform", :multipart => true } do |f| %>
<div>
    <%= f.label :name %>
    <%= f.text_field :name %>


    <%= f.label :description %>
    <%= f.text_area :description %>


    <%= f.fields_for :avatar do |avatar_form| %>
    <%= avatar_form.label :avatar, "Upload" %>
    <%= avatar_form.file_field :avatar, :multiple => true %>
    <% end %>


    <%=f.submit %>
</div>
<% end %>

def create
  @users = User.all
  @user = User.find(params[:user_id])
  @album = @user.albums.build(params[:album])
  if @album.save
    flash[:success] = "Album created!"
  end
end

Pholder::Application.routes.draw do
resources :users do
  resources :albums
end

resources :albums do
  resources :pictures
end

class Album < ActiveRecord::Base
  attr_accessible :avatar, :name, :description
  has_and_belongs_to_many :users

  has_attached_file :avatar
end

def create
  @users = User.all
  @album = Album.new(params[:album].merge!(:user_id => current_user))
  if @album.save
    flash[:success] = "Album created!"
  end
end

def create
  @users = User.all
  @album = Album.new(params[:album])
  @album.user_id = current_user.id
  if @album.save
    flash[:success] = "Album created!"
  end
end