I have a form in one controller(A) that renders a partial from another controller(B), and stays on A's edit page during editing / updating etc.

However... When the partial form form controller B has an error, the error doesn't show up on A's edit page

right now, if there is an error, I am doing (in controller B's update method)

redirect_to :controller => "A", :action => "edit"

and then this is built in... but I don't know what to do with it... the error needs to be sent to controller A... but.. it doesn't

format.xml  { render :xml => @varFromB.errors, :status => :unprocessable_entity }

thanks