save record from gridview

Question

can you Help me how to insert record from gridview ? this is my code .
Thanx.
<asp:Button id ="btnsave" runat="server"></asp:Button">
<asp:GridView ID="GridAssessment" runat="server" AutoGenerateColumns="False" BorderStyle="None">

<Columns>
       <asp:TemplateField HeaderText="KPI">
                                                        <ItemTemplate>
                                                            <asp:Label ID="lblkpi" runat="server" Text='<%#Eval("KPI_Name") %>' />
                                                        </ItemTemplate>
                                                        <FooterTemplate>
                                                            <asp:Label ID="lblscore" runat="server" Text="SCORE"></asp:Label>
                                                        </FooterTemplate>
                                                       
                                                    </asp:TemplateField>                                          
                                                  
  <asp:TemplateField HeaderText="SELF-ASSESSEMENT">
                         <ItemTemplate>
                                                            <asp:DropDownList ID="ddlselfassessment" runat="server">
                                                                <asp:ListItem Value="" Text="--Select--"></asp:ListItem>
                                                                <asp:ListItem Value="1" Text="1"></asp:ListItem>
                                                                <asp:ListItem Value="2" Text="2"></asp:ListItem>
                                                                <asp:ListItem Value="3" Text="3"></asp:ListItem>
                                                                <asp:ListItem Value="4" Text="4"></asp:ListItem>
                                                                <asp:ListItem Value="5" Text="5"></asp:ListItem>
                                                            </asp:DropDownList>
                                                        </ItemTemplate>
</TemplateField>

</Columns>
</GridView>