FormView - Update Process Completes With No Error But Records Is Not Changed

Greetings,

I have setup a FormView which functions as it should but after the user input is updated, the table record stays unchanged, and when I trap the FormView1_ItemUpdated and look at the SqlDataSource1.UpdateCommand, it shows this:

UPDATE [aspnet_test] SET first_name = '', last_name = '', email = '' WHERE id = @original_ID

Here is most of the code I am using:

<asp:FormView ID="FormView1" runat="server"
   DataSourceID="SqlDataSource1" DataKeyNames="id, first_name, last_name"
   OnItemUpdating="FormView1_ItemUpdating" OnItemUpdated="FormView1_ItemUpdated" >
.
. // my ItemEditTempate is here
.
</asp:FormView>

<EditItemTemplate>
First Name: <asp:TextBox Text='<%# Bind("first_name") %>' runat="server" ID="author_name" Columns="20"></asp:TextBox><br />
Last Name: <asp:TextBox Text='<%# Bind("last_name") %>' runat="server" ID="TextBox1" Columns="20"></asp:TextBox><br />
E-mail: <asp:TextBox Text='<%# Bind("email") %>' runat="server" ID="TextBox2" Columns="20"></asp:TextBox><br />
<br />
<asp:Button ID="UpdateButton" runat="server" Text="Update" CommandName="Update" />
<asp:Button ID="CancelButton" runat="server" Text="Cancel" CommandName="Cancel" />
</EditItemTemplate>

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ASPNETDBConnectionString1 %>"

SelectCommand="SELECT id, first_name, last_name, email FROM aspnet_test where id = 1"
UpdateCommand="UPDATE [aspnet_test] SET first_name = '<%# first_name %>',
   last_name = '<%# last_name %>',
   email = '<%# email %>'
   WHERE id = @original_ID ">

<UpdateParameters>
<asp:Parameter Name="original_ID" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>

Any idea where the @original_ID is supposed to get its value from, or why does the SQL command shows blank fields?

Thanks

Eric.