What's the problem with paginate?

I'm new in rails, but it attracts me so much. When i learn "Agile Web Development with Rails, 2nd Edition", i find that 'pagniate' is very useful. But when i try to make a sample by myself, the pagniate seems uneffective. No matter what the param 'page' is, it will only list the first page items. My source code is as simple as 1 def list 2 @agent_relationship_pages, @agent_relationships = paginate :agent_relationships, :per_page => 4 3 end If i change line 2 to 2 @agent_relationship_pages, @agent_relationships = paginate :agent_relationships, :per_page => 4, :page => params[:page]

error page comes, and shows "Unknown options: page"

What happens?