Determine if client has flash installed.

Hi,
Got a web site and on its index.html a script gets ran to determine if a user has flash installed. If they do, they get re-directed to index1.html if not they get re-directed to index2.html

Works great, but with that in place we have a problem with trying to get our site indexed on google or any other search engine.

Anyone have a better method to determin if a user can view our flash banner or not and how to take care of them accordingly with out hurting our indexing on search engines?

Thanks guys.