How Rails pick a view template if it's Mobile and a AJAX call

I'm implementing Mobile Web on开发者_如何学JAVA my Rails App. So this is what I have in my folder:

index.html.erb
index.js.erb (for pagination)
index.mobile.erb
index.mobile.js.erb (?? this does not work)

So i'm doing AJAX paging as well for my mobile web. I keep getting Rails view template error:

ActionView::MissingTemplate (Missing template .../index with {:handlers=>[:builder, :rjs, :rhtml, :rxml, :erb], :locale=>[:id, :id], :formats=>[:mobile]} in view paths "/Users/.../app/views"):

Anyone done this before? Thanks :)