How do I fix a 'No route matches' error when loading a flash burndown chart?

Question

@graph = open_flash_chart_(880, 450,
                           url_for(:action => 'get_graph_data',
                                   :project_id => @project.id,
                                   :version_id => @version.id),
                           true)

I am creating a burndown chart but the chart is not visible showing the error:

No route matches {:action=>"get_graph_data", :controller=>"version_burndown_charts", :project_id=>1, :version_id=>1}