Thanks for the clarification
As Laurent says, the above control is entirely client-side. This has two
main advantages:
1) switching between tabs doesn't cause a round-trip to the server and back,
thereby minimising network traffic and reducing the load on your webserver
2) the contents of *all* of the tabs are loaded all of the time, thereby
allowing client-side comparison validation between controls on different
tabs
The main disadvantage is that the control will not work if the user has
disabled JavaScript. Whether that is important or not is, of course, another
argument - and one which has been discussed several times in this
newsgroup...
If you're interested in using the above tab control, please contact me
privately - it is absolutely full of bugs, and doesn't work at all with
ASP.NET v2, especially MasterPages, so I have made a whole slew of
modifications and enhancements to it, including the ability to remember the
current tab without needing to use a cookie (I'm not kidding - that's how it
originally did it!!!), the ability to enable / disable tabs rather than just
hide them, full ASP.NET v2 support etc...
Alternatively, if you want a solution which will work without JavaScript,
there are several commercial products available or, if you're using ASP.NET
v2, you could roll your own with a combination of a couple of the new v2
webcontrols:
http://www.codeproject.com/aspnet/TabControl.asp. This will, of
course, force a postback every time you switch tabs, and only the contents
of the *current* tab will be downloaded to the client at any given time, but
it *will* work with JavaScript disabled...