I'm creating a website for a client in which he wants a link that people can click on to go back to the previous website design and go to that design every time they go back to that website.
How would I go about doing this?
Would I need to create a cookie and if I do how do I do that?
Thanks for all your help, I'll come back to this question when I get to doing this part!
How much different is the new design? Is it just a manner of the look, or are there significant differences in the flow and features of the new design? Are they using the same database setup, or did things change between the old and new versions? Should they be able to use either site to do the same things? For instance, if they create a record on the new site, should it show up on the old site?
If there's minimal change, the easiest thing might be to just punt and run the old site as it's own website. Put a big link on the new site that says "If you want the old site, visit oldsite.example.com". It's usually nice to figure out how you can socially engineer the customers to want to use the new site instead, and also tell them that the old site will be disappearing permanently at some point.
I'd be very reluctant to infect a new system with hooks to support an old system you want to move away from.
You might consider placing the old app in a subdomain, like "old.mydomain.com" or something similar. This will allow you to maintain the applications in separate( IIS?) folders and separate projects.
If you don't want to use a subdomain, you could use a rewrite engine to check for a cookie setting such as "UseOldSite=TRUE" and rewrite to the old application where appropriate.
Some issues that you might encounter with this approach would be the use of absolute urls and paths within the application and sharing of session or cookie data.
I've noticed that GMail provides a "view in HTML" option which minimizes the use of JavaScript. I assume this is for compatibility with older browsers with minimal or insufficient JavaScript support, but the approach may be applicable to your situation.
A good option ( assuming there are no structural changes in the data ) is to use Alternate Style Sheets.
This is a great post on switching between stylesheets.
Of course, in FF, you can go to: View > Page Style > Other Style Sheet.