Cannot Edit or Delete using GridView and FormView

 I am new to .Net and used the GridView and FormView to manage my data in SQL database. I configured the SQLDataSource correctly to allow Input, Edit and Delete to function. I have only been able to View and Add a new item using the FormView.  
I am able to select an item in the list but when I go to make changes and click on the "Update" button, nothing changes. Same with the Delete button.
Can someone tell me what I am doing wrong? Or if I need to manually input other coding?  
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