Error on update of Datalist

<script> 
    Protected Sub dlContacts_EditCommand(ByVal source As Object, ByVal e As DataListCommandEventArgs)
        dlContacts.EditItemIndex = e.Item.ItemIndex
        dlContacts.DataBind()
    End Sub
    
    Protected Sub dlContacts_DeleteCommand(ByVal source As Object, ByVal e As DataListCommandEventArgs)
        srcContacts.DeleteParameters("fcntct_id").DefaultValue = dlContacts.DataKeys(e.Item.ItemIndex).ToString()
        srcContacts.Delete()
    End Sub
    
    Protected Sub dlContacts_CancelCommand(ByVal source As Object, ByVal e As DataListCommandEventArgs)
        dlContacts.EditItemIndex = -1
        dlContacts.DataBind()
    End Sub
    
    Protected Sub dlContacts_UpdateCommand(ByVal source As Object, ByVal e As DataListCommandEventArgs)
        Dim txtFirstName As TextBox = CType(e.Item.FindControl("fcntct_fname"), TextBox)
        Dim txtLastName As TextBox = CType(e.Item.FindControl("fcntct_lname"), TextBox)
        Dim txtEmail As TextBox = CType(e.Item.FindControl("fcntct_email"), TextBox)
      
        srcContacts.UpdateParameters("fcntct_id").DefaultValue = dlContacts.DataKeys(e.Item.ItemIndex)
        srcContacts.UpdateParameters("fcntct_fname").DefaultValue = txtFirstName.Text
        srcContacts.UpdateParameters("fcntct_lname").DefaultValue = txtLastName.Text
        srcContacts.UpdateParameters("fcntct_email").DefaultValue = txtEmail.Text
        
        'update the datasource
        srcContacts.DataBind()
        
        'take out of edit mode
        dlContacts.EditItemIndex = -1
        
    End Sub
</script>
 
<asp:SqlDataSource ID="srcCustomers" runat="server" ConnectionString="<%$ ConnectionStrings:USASqlServer %>"
    SelectCommand="SELECT cm_addr + ' - ' + cm_sort AS [name], cm_addr, cm_sort&#13;&#10;FROM cm_mstr">
</asp:SqlDataSource>
<asp:SqlDataSource ID="srcContacts" runat="server" ConnectionString="<%$ ConnectionStrings:FastSqlServer %>"
    DeleteCommand="DELETE FROM [fcntct_mstr] WHERE [fcntct_id] = @fcntct_id" 
    InsertCommand="INSERT INTO [fcntct_mstr] ([fcntct_fname], [fcntct_lname], [fcntct_email]) VALUES (@fcntct_fname, @fcntct_lname, @fcntct_email)"
    SelectCommand="SELECT [fcntct_fname], [fcntct_lname], [fcntct_email], [fcntct_id] FROM [fcntct_mstr]"
    UpdateCommand="UPDATE [fcntct_mstr] SET [fcntct_fname] = @fcntct_fname, [fcntct_lname] = @fcntct_lname, [fcntct_email] = @fcntct_email WHERE [fcntct_id] = @fcntct_id">
    <DeleteParameters>
        <asp:Parameter Name="fcntct_id" Type="Int16" />
    </DeleteParameters>
    <UpdateParameters>
        <asp:Parameter Name="fcntct_fname" />
        <asp:Parameter Name="fcntct_lname" />
        <asp:Parameter Name="fcntct_email" />
        <asp:Parameter Name="fcntct_id" />
    </UpdateParameters>
    <InsertParameters>
        <asp:Parameter Name="fcntct_fname" Type="String" />
        <asp:Parameter Name="fcntct_lname" Type="String" />
        <asp:Parameter Name="fcntct_email" Type="String" />
    </InsertParameters>
</asp:SqlDataSource>
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="srcCustomers" DataTextField="name"
    DataValueField="cm_addr" >
</asp:DropDownList>
<br />
<br />
<asp:DataList ID="dlContacts" runat="server" 
            DataKeyField="fcntct_id" 
            DataSourceID="srcContacts"
            OnEditCommand="dlContacts_EditCommand" 
            OnCancelCommand="dlContacts_CancelCommand"
            OnDeleteCommand="dlContacts_DeleteCommand"
            OnUpdateCommand="dlContacts_UpdateCommand" >
    <EditItemTemplate>
        <asp:ImageButton
            ID="btnSave"
            CommandName="Update"
            ImageUrl="~/images/save.gif"
            AlternateText="Save Contact"
            runat="server" />&nbsp;&nbsp;  
        <asp:ImageButton
            ID="btnCancel"
            CommandName="Cancel"
            AlternateText="Cancel" 
            ImageUrl="~/images/cancel2.gif"
            OnClientClick="return confirm('Cancel without save?');"
            runat="server" /><br /><br />
        fcntct_fname:
        <asp:Textbox ID="fcntct_fnameLabel" runat="server" Style="position: static" Text='<%# Eval("fcntct_fname") %>'></asp:Textbox><br />
        fcntct_lname:
        <asp:Textbox ID="fcntct_lnameLabel" runat="server" Style="position: static" Text='<%# Eval("fcntct_lname") %>'></asp:Textbox><br />
        fcntct_email:
        <asp:Textbox ID="fcntct_emailLabel" runat="server" Style="position: static" Text='<%# Eval("fcntct_email") %>'></asp:Textbox>
    </EditItemTemplate>
    <ItemTemplate>
        <asp:ImageButton 
                ID="btnEdit" 
                CommandName="Edit"
                AlternateText="Edit Contact" 
                ImageUrl="~/images/edit.gif"
                runat="server" />&nbsp;
        <asp:ImageButton 
                ID="btnDelete"
                CommandName="Delete" 
                AlternateText="Delete Contact"
                OnClientClick="return confirm('Are you sure?');"
                ImageUrl="~/images/delete.gif"
                runat="server" />
        <br /><br />
        fcntct_fname:
        <asp:Label ID="fcntct_fnameLabel" runat="server" Text='<%# Eval("fcntct_fname") %>'></asp:Label><br />
        fcntct_lname:
        <asp:Label ID="fcntct_lnameLabel" runat="server" Text='<%# Eval("fcntct_lname") %>'></asp:Label><br />
        fcntct_email:
        <asp:Label ID="fcntct_emailLabel" runat="server" Text='<%# Eval("fcntct_email") %>'></asp:Label><br />
        fcntct_id:
        <asp:Label ID="fcntct_idLabel" runat="server" Text='<%# Eval("fcntct_id") %>'></asp:Label>
    </ItemTemplate>
</asp:DataList>