+ anchor = []
+
+ if params[:lat] && params[:lon]
+ anchor << "map=#{params.delete(:zoom) || 5}/#{params.delete(:lat)}/#{params.delete(:lon)}"
+ end
+
+ if params[:layers]
+ anchor << "layers=#{params.delete(:layers)}"
+ elsif params.delete(:notes) == 'yes'
+ anchor << "layers=N"
+ end
+
+ if anchor.present?
+ redirect_to params.merge(:anchor => anchor.join('&'))
+ return
+ end
+