FileUpload In FormView Inside An UpdatePanel

I have an ASP.Net webpage which I intend to use for letting the user(not the real users, but content manager basically) insert and edit the records in a table using a FormView. This FormView is inside an UpdatePanel, as I'm also using cascading dropdownlists to let the user select some values. Now, this FormView also contains 4 FileUpload controls, and as you might know that these fileupload controls require a full postback since most browsers do not let Javascript access the disk. So, this problem would have been solved by doing something like:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="InsertButton" />
<asp:PostBackTrigger ControlID="UpdateButton" />
</Triggers>
<ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>

Edit: Forgot to add that the fileuploading takes place in the OnUpdating and OnInserting events of the SqlDataSource. The Problem: Since the InsertButton and the UpdateButton reside inside the Formview, I cannot directly access their ID's through markup. And MSDN says that: Programmatically adding PostBackTrigger controls is not supported. A workable solution for me was to set the UpdatePanel's PostBackTrigger as the whole FormView itself:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:PostBackTrigger ControlID="FormView1" />
</Triggers>
<ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>

But now due to a bit of change in requirements, this solution(if you call it a solution) is not acceptable.