How to get the selected content from the grid-view using select option in gridview control in the detail view fields

Have a look at the link selecting gridview row
http://msmvps.com/blogs/deborahk/archive/2010/01/25/asp-net-selecting-a-row-in-a-gridview.aspx

Then populate the details view with the selected row values of gridview based on the record id.