Display AJAX ModalPopupExtender inside RowCommand event of GridView in ASP.Net

Here Mudassar Ahmed Khan has explained with an example, how to display AJAX ModalPopupExtender Modal Popup inside RowCommand event of GridView in ASP.Net using C# and VB.Net. Inside the GridView OnRowCommand event handler, the GridView Selected Row details will be fetched and displayed in the ASP.Net AJAX ModalPopupExtender Modal Popup.