buffering

[sam]

I have a few processing-intensive aspx forms. I want to
display an animated gif while the user is waiting for the
form to load. I have tried a number of ways to do this
but each is unsuccessful.
I figured buffering controls this. I have set the
following:
Response.Buffer=false - in my page_init.
Buffer = false - on my aspx document properties.
Removed tick from Enable buffering in IIS Application
Configuration.

I have tied setting Response.Buffer=True then calling
Response.Flush in the page.load, but that didn't work.

Any suggestions would be greatly appreciated
regards
Sam