I am sorry, but this is still not supported in the current version of the controls. I have added this feature request in PITS. You can view it here
. You can vote for it, track its status and see when it is going to be implemented.
the Telerik team
Register for the Q2 2011 What's New Webinar Week. Mark your calendar for the week starting July 18th and book your seat for a walk through of all the exciting stuff we will ship with the new release!