how to bind calenar control to dropdownlist in asp.net.

I think you are saying that when anyone clicks the drop down the calender controls open and allow to select the value from that.If i am right than you cannot able to do that directly with the given controls from Visual Studio rather you have to use open source library of ASP.NET AJAX Toolkit you can do this very easily with this. If you have any with this feel free to revert back.