Eric,
I don't think that using a URL for the series name is the best approach.... anyway did you try to debug the action to see what value you are getting from DataPoint_GetClicked and what you are passing to the external URL?
I don't think that using a URL for the series name is the best approach.... anyway did you try to debug the action to see what value you are getting from DataPoint_GetClicked and what you are passing to the external URL?