Display Message when Registration hits 0

Current Background: I have a ASP.NET VB form connected to a database. In the database, there is a field called TourCount. This count decrimates by 1 everytime a user submits a form.

Goal: When the TourCount reaches 0, all registrations must close. However, at the moment, TourCount continues to decrimate into negative numbers. When TourCount reaches 0, I would like a message to appear above the form saying "Registration Closed".

Current Attempt: I have tried a few things, but I'm not sure where it's going. I don't receive a config error message, but it's never functioning correctly either. I'm not sure where or what type of script I should be using. My logic says, when TourCount is less than or equal to zero, display a text string via the id called "Message".

        <asp:SqlDataSource id="SqlDataSrcTourCount" runat="server" ConnectionString="<%$ ConnectionStrings:recruitmentConnectionString %>" SelectCommand = "SELECT [TourCount] FROM [tourdates] WHERE [TourType] = @TourType AND [TourDatesAvailable] = @TourDates" ProviderName="System.Data.SqlClient" UpdateCommand="UPDATE [tourdates] SET [TourCount] = ([TourCount] - 1) WHERE [TourType] = @TourType AND [TourDatesAvailable] = @TourDates">
            <SelectParameters>
                <asp:Parameter Name="TourType" DefaultValue="JobFair"></asp:Parameter>
                <asp:Parameter Name="TourDates" Type="String"></asp:Parameter>
            </SelectParameters>
            <UpdateParameters>
                <asp:parameter Name="TourType" DefaultValue="JobFair"></asp:Parameter>
                <asp:parameter Name="TourDates" Type="String"></asp:Parameter>
            </UpdateParameters>
        </asp:SqlDataSource>

        <script type="text/javascript">
            If (TourCount <= 0) {
                document.getElementById("Message").style.display = "inline";
                return true;
            }
            else {
                document.getElementById("Message").style.display = "none";
                return false;
            }
        </script>

In the HTML: <span id="Message">-Closed-</span>

If anyone could provide me with some insight about how to proceed, I would truly appreciate your help. Thank you so much for your开发者_高级运维 time in reading.

I'm wondering, why are you using javascript for this?

If I was you I'd simply get the TourCount on PageLoad Navigate to your closed.asmx if TourCount = 0 else when they hit the Submit button get the TourCount again (it could've changed in the meantime) If still > 0 do the registration and reduce TourCount If 0 navigate to the 'too slow slowpoke' page.

The only thing I'd use javascript for is dynamically refreshing TourCount every x seconds and automatically navigating to closed.asmx when it hits 0.