I'm writing an web-app that keeps track of deadlines. With this app you have to be able to update records that are being saved in an SQL DB. However I'm having some problem with my update in my aspx-file.

    <asp:GridView ID="gv_editMilestones" runat="server" DataSourceID="sql_ds_milestones" 
    CellPadding="4" ForeColor="#333333" GridLines="None" Font-Size="Small" 
    AutoGenerateColumns="False" DataKeyNames="id" Visible="false"
    onrowupdated="gv_editMilestones_RowUpdated" 
    onrowupdating="gv_editMilestones_RowUpdating" 
    onrowediting="gv_editMilestones_RowEditing">
    <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
    <Columns>
        <asp:CommandField ShowEditButton="True" />
        <asp:BoundField DataField="id" HeaderText="id" SortExpression="id" 
            ReadOnly="True" Visible="false"/>
        <asp:BoundField DataField="ms_id" HeaderText="ms_id" 
            SortExpression="ms_id" ReadOnly="True"/>
        <asp:BoundField DataField="ms_description" HeaderText="ms_description" 
            SortExpression="ms_description"/>  
<%--        <asp:BoundField DataField="ms_resp_team" HeaderText="ms_resp_team" 
            SortExpression="ms_resp_team"/>--%>
        <asp:TemplateField HeaderText="ms_resp_team" SortExpression="ms_resp_team">
            <ItemTemplate>
                <%# Eval("ms_resp_team") %>
            </ItemTemplate>
            <EditItemTemplate>
                <asp:DropDownList ID="DDL_ms_resp_team" runat="server"
                    DataSourceID="sql_ds_ms_resp_team" DataTextField="team_name"
                    DataValueField="id">
                    <%--SelectedValue='<%# Bind("ms_resp_team") %>'--%>
                </asp:DropDownList>
            </EditItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="ms_focal_point" HeaderText="ms_focal_point" 
            SortExpression="ms_focal_point" />
        <asp:BoundField DataField="ms_exp_date" HeaderText="ms_exp_date" 
            SortExpression="ms_exp_date" DataFormatString="{0:d}"/>
        <asp:BoundField DataField="ms_deal" HeaderText="ms_deal" 
            SortExpression="ms_deal" ReadOnly="True"/>
        <asp:CheckBoxField DataField="ms_active" HeaderText="ms_active" 
            SortExpression="ms_active"/>
    </Columns>
    <FooterStyle BackColor="#CCCC99" />
    <PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
    <SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />
    <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
    <AlternatingRowStyle BackColor="White" />
    <EditRowStyle BackColor="#999999" />
</asp:GridView>
<asp:SqlDataSource ID="sql_ds_milestones" runat="server" 
    ConnectionString="<%$ ConnectionStrings:testServer %>" 
    SelectCommand="SELECT [id]
                          ,[ms_id]
                          ,[ms_description]
                          ,(SELECT [team_name] FROM [NSBP].[dbo].[tbl_teams] as teams
                            WHERE milestones.[ms_resp_team] = teams.[id]) as 'ms_resp_team'
                          ,[ms_focal_point]
                          ,[ms_exp_date]
                          ,(SELECT [deal] FROM [NSBP].[dbo].[tbl_deals] as deals
                            WHERE milestones.[ms_deal] = deals.[id]) as 'ms_deal'
                          ,[ms_active]
                          FROM [NSBP].[dbo].[tbl_milestones] as milestones"
    UpdateCommand="UPDATE [NSBP].[dbo].[tbl_milestones]
                   SET [ms_description] = @ms_description
                   ,[ms_focal_point] = @ms_focal_point
                   ,[ms_active] = @ms_active
                   WHERE [ms_id] = @ms_id">
    <UpdateParameters>
        <asp:Parameter Name="ms_description" Type="String" />
<%--            <asp:Parameter Name="ms_resp_team" Type="String" />--%>
        <asp:Parameter Name="ms_focal_point" Type="String" />
        <asp:Parameter Name="ms_exp_date" Type="DateTime" />
        <asp:Parameter Name="ms_active" Type="Boolean" />
<%--            <asp:Parameter Name="ms_id" Type="String" />--%>
    </UpdateParameters>
</asp:SqlDataSource>

You can see my complete GridView-structure + my datasource bound to this GridView. There is nothing written in my onrowupdating-function in my code-behind file.

Thx in advance