SEO dynamic / AJAX pages

I have a very 开发者_C百科dynamic / ajax powered website which also includes iframes and due this reason I have a very bad SEO rank and it come in my mind to make one more additional version of the site (text based / no script) and serve it to the search engines based on the user agent . Please let me know if you think that is a feasible method and if it's not what else would you recommend me to do .. I don't want to loose any fancy ajax feature but I also need to keep the website on the google map :) thank you in advance for any answer ! btw the website is developed in asp.net c# .

Why not just refactor the site properly in the first place, instead of maintaining multiple copies? It's more effort up front, but will be less effort in the long-run.