def store_location location=nil
    session[:return_to] = location || request.request_uri
end

def redirect_back_or_default(default)
    redirect_to(session[:return_to] || default)
    session[:return_to] = nil
end

def http_referrer
  http_referer, request_path  = request.env["HTTP_REFERER"], 
                                request.env["REQUEST_PATH"]
  return nil  unless (http_referer and request_path and 
                      http_referer =~ Regexp.new("^#{SITE_ROOT}") and
                      http_referer != (SITE_ROOT + request_path))
  return http_referer    
end 
     
before_filter :store_location, :only => [:new, :edit]

def store_location
  super http_referrer
end 
     
def create
  if @user.save
    flash[:notice] = "Successfully created the user."
    redirect_back_or_default root_url
  else
    render :action => 'new'
  end
end    

def update
  if @user.save
    flash[:notice] = "Successfully created the user."
    redirect_back_or_default root_url
  else
    render :action => 'new'
  end
end