Delegates Study

http://www.akadia.com/services/dotnet_delegates_and_events.html
http://www.c-sharpcorner.com/UploadFile/Ashush/Delegates02152008155757PM/Delegates.aspx
http://www.codersource.net/csharp_delegates_events.html
http://www.developerfusion.com/article/3057/events-and-delegates/
http://www.csharp-station.com/Tutorials/lesson14.aspx

Radio button in Repeater Control Issue

Only one radio button should be checked.
Solution

http://stackoverflow.com/questions/290018/how-to-find-checked-radiobutton-inside-repeater-item

For Fixing the Issue

http://www.codeguru.com/csharp/csharp/cs_controls/custom/article.php/c12371/