How To Update Multiple Tables With Updatecommand

 hi all,
i'm working on a formview which will update 2 tables which are linked together but..i'm getting an error of the control not being found.my code is as shown below
                           <asp:SqlDataSource ID="invDetSrc" runat="server"
                                               ConnectionString="<%$ ConnectionStrings:rockwellConnectionString %>"
                                               ProviderName="<%$ ConnectionStrings:rockwellConnectionString.ProviderName %>"
                                               SelectCommand="SELECT rockwell.logix_asset_list.Inventory_ID, rockwell.vendor.Vendor_Name, rockwell.logix_asset_list_category.Category_Name, rockwell.logix_asset_list.Total_Quantity, rockwell.logix_asset_list.Quantity_In_Stock, rockwell.logix_asset_list.Part_Number, rockwell.logix_asset_list.On_Order, rockwell.logix_asset_list.ImageUrl, rockwell.logix_asset_list.DrawingUrl, rockwell.logix_asset_list.Description FROM rockwell.logix_asset_list, rockwell.logix_asset_list_category, rockwell.vendor WHERE rockwell.logix_asset_list.Logix_Asset_List_Category_ID = rockwell.logix_asset_list_category.Logix_Asset_List_Category_ID AND rockwell.logix_asset_list.Vendor_ID = rockwell.vendor.Vendor_ID AND&#13;&#10;rockwell.logix_asset_list.Part_Number = ?"
                                               UpdateCommand="UPDATE vendor, logix_asset_list
                                               set
                                               vendor.vendor_name= @Vendor_Name,
                                               logix_asset_list.Total_Quantity=@Total_Quantity,
                                               logix_asset_list.Quantity_In_Stock=@Quantity_In_Stock,
                                               logix_asset_list.Part_Number=@Part_Number,
                                               logix_asset_list.On_Order=@On_Order,
                                               logix_asset_list.Description=@Description
                                               WHERE
                                               logix_asset_list.Vendor_ID = vendor.Vendor_ID
                                               and logix_asset_list.Inventory_ID = @Inventory_ID" >
                               <SelectParameters>
                                   <asp:ControlParameter ControlID="rstGrid" Name="?" PropertyName="SelectedValue" />
                               </SelectParameters>
                               <UpdateParameters>
                               <asp:ControlParameter Type="Int32" ControlID="Total_Quantity" ConvertEmptyStringToNull="true" Name="@Total_Quantity"/>
                               <asp:ControlParameter Type="string" ControlID="Vendor_Name" ConvertEmptyStringToNull="true" Name="@Vendor_Name"/>
                               <asp:ControlParameter Type="Int32" ControlID="Quantity_In_Stock" ConvertEmptyStringToNull="true" Name="@Quantity_In_Stock"/>
                               <asp:ControlParameter Type="string" ControlID="Part_Number" ConvertEmptyStringToNull="true" Name="@Part_Number"/>
                               <asp:ControlParameter Type="string" ControlID="On_Order" ConvertEmptyStringToNull="true" Name="@On_Order"/>
                               <asp:ControlParameter Type="string" ControlID="Description" ConvertEmptyStringToNull="true" Name="@Description"/>
                               <asp:ControlParameter Type="Int32" ControlID="Inventory_ID" ConvertEmptyStringToNull="true" Name="@Inventory_ID"/>
                               </UpdateParameters>
                            </asp:SqlDataSource>
 <asp:FormView ID="FormView1" runat="server" BackColor="White" BorderColor="#DEDFDE"
                                BorderStyle="None" BorderWidth="1px" CellPadding="4" DataSourceID="invDetSrc"
                                ForeColor="Black" GridLines="Vertical" DataKeyNames="Inventory_ID">
 <EditItemTemplate>
                                    <table border="0" cellpadding="3" cellspacing="3" style="background-color: white; color: black;">
                                        <tr>
                                            <td colspan="2">
                                                <asp:Image ID="Image1" runat="server" Height="150px" ImageUrl='<%# "~/Image/photo/Logix%20Asset/"+Eval("Category_Name")+"/"+Eval("ImageUrl") %>'
                                                    Width="150px" />
                                                <br />
                                                <asp:HyperLink ID="drawingLink" runat="server" NavigateUrl='<%# "~/Image/drawing/Logix%20Asset/"+Eval("Category_Name")+"/"+Eval("DrawingUrl") %>'
                                                    Target="_blank" Text="View Drawing" ForeColor="Blue"></asp:HyperLink>
                                            </td>
                                            <asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Bind("Inventory_ID") %>' />
                                        </tr>
                                        <tr>
                                            <td style="color: black">
                                                Part Number:</td>
                                            <td>
                                                <asp:TextBox ID="Part_Number" runat="server" Text='<%# Bind("Part_Number")%>'></asp:TextBox>
                                                </td>
                                        </tr>
                                        <tr>
                                            <td>
                                                <strong style="color: black">Vendor:</strong></td>
                                            <td>
                                                <asp:TextBox ID="Vendor_Name" runat="server" Text='<%# Bind("Vendor_Name")%>'></asp:TextBox>
                                                </td>
                                        </tr>
                                        <tr>
                                            <td style="color: black">
                                                <strong>Total Quantity:</strong></td>
                                            <td>
                                                <asp:TextBox ID="Total_Quantity" runat="server" Text='<%# Bind("Total_Quantity")%>'></asp:TextBox>
                                                </td>
                                        </tr>
                                        <tr>
                                            <td style="color: black">
                                                <strong>Quantity In Stock:</strong></td>
                                            <td>
                                                <asp:TextBox ID="Quantity_In_Stock" runat="server" Text='<%# Bind("Quantity_In_Stock")%>'></asp:TextBox>
                                         </td>
                                        </tr>
                                        <tr>
                                            <td style="color: black">
                                                <strong>Quantity on Order:</strong></td>
                                            <td>
                                                <asp:TextBox ID="On_Order" runat="server" Text='<%# Bind("On_Order")%>'></asp:TextBox>
                                            </td>
                                        </tr>
                                        <tr>
                                            <td style="color: black; height: 44px;">
                                                <strong>Description:</strong></td>
                                            <td style="height: 44px">
                                            <asp:TextBox ID="Description" runat="server" Text='<%# Bind("Description")%>' Height="53px" TextMode="MultiLine" Width="150px"></asp:TextBox></td>
                                        </tr>
                                        <tr>
                                            <td>
                                                <asp:Button ID="EditBtn" runat="server"
                                                    Text="Submit Changes" Width="106px" CommandName="Update" /></td>
                                            <td>
                                                &nbsp;<asp:Button ID="Cancel" runat="server" Text="Cancel" CommandName="cancel" /></td>
                                        </tr>
                                    </table>
                                </EditItemTemplate>
                            </asp:FormView>
any help would be much appreciated!