Hi,

I think you are truing to use cascading dropdownlist and in the change of the second dropdownlist you want to populate the radio button list. check the following post-

http://forums.asp.net/p/1723443/4610124.aspx/1?Re+Unable+to+get+data+list+from+server+code+

In this post you can find how to call the controller method form jQuery. And in the letter part of the post you can see the example of the cascadsing dropdown list.