how to get a single row value from gridview when i click on select button of gridview

i have written this code for getting the value but it not working
<form id="form1" runat="server"> <div> <table> <tr> <td> <asp:GridView ID="GridView1" runat="server" DataKeyNames="Id" Width="252px" OnSelectedIndexChanging="GridView1_SelectedIndexChanging"> <Columns> <asp:TemplateField> <ItemTemplate> <asp:Button ID="selc" runat="server" CommandName="Select" Text="Select"/> </ItemTemplate> ...