insert IPAddress into SQL server through detailsview

I need to collect user IP addresses. I cannot figure out what to put into template field TextBox of DetailsView to insert the IP addresses into SQL server.

Dim hostname As String = Server.HtmlEncode(Request.UserHostName)    

Here is the DetailsView and Insert command
 InsertCommand="INSERT INTO [table] ([IPAddress]) VALUES (@IPAddress)"
          <InsertParameters>
              <asp:Parameter Name="IPAddress" Type="String" />
          </InsertParameters>

          <asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="False"
                  DataKeyNames="ID" DataSourceID="SqlDataSource1" DefaultMode="Insert"
                  EnableModelValidation="True" Height="50px" Width="125px">
                  <Fields>
                      <asp:TemplateField HeaderText="IPAddress" SortExpression="IPAddress">
                          <EditItemTemplate>
                              <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("IPAddress") %>'></asp:TextBox>
                          </EditItemTemplate>
                          <InsertItemTemplate>                        
   <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("IPAddress")">'/>                  
                            </InsertItemTemplate>
                          <ItemTemplate>
                              <asp:Label ID="Label1" runat="server" Text='<%# Bind("IPAddress") %>'></asp:Label>
                          </ItemTemplate>
                      </asp:TemplateField>
                      <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False"
                          ReadOnly="True" SortExpression="ID" />
                      <asp:CommandField ShowInsertButton="True" />
                  </Fields>
              </asp:DetailsView>
              <br />