Rotating an image in Image control using C# in web application

Hi to all..
I had a problem, I am developing a web application. In one page I have one Image(System.web.UI.Image) Control. I want to rotate the image in that control on button click event. I had done to some extend where the image is converted to bitmap and rotated. Now I want to convert the bitmap(System.Drawing.image) to Image(System.Web.UI.Image). I tried alot but am not getting...

Please help me...

Thanks in Advance......