I have a client that would like me to redo their website.  When we started talking it was a simple redo from their old provider but  they have now thrown a wrench into it that I am not sure how to handle.  This client is a small manufacturer and they want some info available to their wholesale clients that actually purchase from them and then they want other information for the general public so they can learn about the products and then go to their local commercial installer to buy it.  They would like the following to happen:

·          When someone comes to the site for the first time they want the user to click on a button that then directs them to the appropriate information/part of the site.  That is one button that says residential and one that says commercial.

·         They would really like a cookie to be created so the next time the person comes to the site they don't have to choose again.  I guess it would be good to have a way so that a person can change their choice in case they got confused when they first chose.  :O)

·         Once on the residential or commercial side the menus etc. would all be about that part of the site although maybe a button or something to go to the other part would be useful.  My biggest concern here is how to have two different menus.  Of course I am sure there will be many pages that will be unique and some that will be common between the two.

Can some of this be done using subdomains, child sites etc.  Sorry, I know enough to be dangerous!

Any guidance would be appreciated.  We are more designers than programmers so that is part of our problem.