insert update and delete by using gridview in ASP.NET 4.0

Question

Hi.......
This is Sharda Vishwakarma
I have a problem belong to insert update and delete by using gridview. I'm doing that but i'm geting runtime exception and I'm also trying to get help from
Your website  but i'm not able to understand the source code so please help step by step with printscreen.

Thanks & Regards

Sharda Vishwakarma

Kindly Revert back
([email protected])