Refactoring RJS

I have some RJS that could use some refactoring. I use the function called with afterFinish twice and Im wondering what the best way to refactor is. This is all inline rjs in the controller mind you:

          page.visual_effect :slide_down, "add_appt_#{params [:day]}", :afterFinish => "function(){       $('end_drop_#{params[:day]}_#{params [:appt_counter]}').style.display = 'block';       $('end_drop_#{params[:day]}_#{params [:appt_counter]}').style.visibility = 'hidden';       $('start_drop_#{params[:day]}_#{params [:appt_counter]}').style.display = 'block';       $('start_drop_#{params[:day]}_#{params [:appt_counter]}').style.visibility = 'hidden';           }"