thanks for a reply.
Well the issue is that i don't want to increase the size of my codes, so script is not an option for me, if i was going to use script i would have used images for corners it would have been better as they would have small size then this script size. Plus it would work in all browsers, but again script and images i am not going to use them and i don't want rounded corners in other IE version just in IE 9. As its going to be used for my site which is for up to date people. if they are using out of date versions its their problem not mine.