Hi,
I am not good at css but I have to transfer my old navigation bar to tab control. I have read this article
http://www.telerik.com/help/aspnet/tabstrip/tabsrip_cssstylesfornormalstate.html

but I dun really know how to implement it if I have configured all the li, ul, a hover b4..Would u mind to upload the example code of the above article?

I have solved this problem.
First, u can base on the build-in skin to modify on this web site. This is very useful tool, so it should be put on somewhere we can see easily on the this web.
http://stylebuilder.telerik.com/

After u have created a new css style, set yr tab property

Then all things should be good to go.