Redirect on Button click in ASP.Net GridView

i ahve grid view where i have used an button on click it redirects to other page now i want to transfer the primarykey value of selected row to other page

this code is of button event 
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        Session.Add("id",GridView1.SelectedValue);
        Response.Redirect("trail.aspx");
        
    }

this is grid view html
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns = "False" 
            Font-Names = "Arial" Caption = "Using ImageField" DataKeyNames="ID" 
            onrowcommand="GridView1_RowCommand">
            <Columns>
                <asp:BoundField DataField = "ID" HeaderText = "ID" />
                <asp:BoundField DataField = "Name" HeaderText = "Image Name" />
                <asp:ImageField DataImageUrlField = "ID"
                    DataImageUrlFormatString = "ImageCSharp.aspx?ImageID={0}"
                     ControlStyle-Width = "100" ControlStyle-Height = "100"
                     HeaderText = "Preview Image">
                <ControlStyle Height="100px" Width="100px"></ControlStyle>
                </asp:ImageField>
                
                
                <asp:ButtonField Text="Button" />
                
                
            </Columns>
        </asp:GridView>