Flash web site - need for robots.txt?

I have a web site in Flash - is it necessary to have a robots.txt file?

[Cratima]

My web site is fully in Flash, I only have index.html non-Flash (yes, and a guidelines file, but that's really not important).

Question is: do I need a robots.txt if the web site is in Flash? Is there any use to tell Google to index, well, the index.html file?

[jay5r]

robots.txt is used to tell spiders what NOT to crawl.

Flash is pretty useless to search engines - there's not much in it they can index. However, they may evaluate your flash file for links to other pages. If you have external links in your flash movie and you don't want them known by spiders, then you might set up a robots.txt file to tell them to not index your site, but you can't use it to tell them to index your site (for that you'd use a sitemap).