Update:

I just realized that the file code you posted was an attempt to output the GIF to the agent browser. At first, from the context of your post, I had made the assumption that you were building the GIF with your snippet.

What you want to do is simply tell the agent, calling on the web server, where the file to be displayed lives. You can do that using the IMG tag. You will also want to build the GIF in a place that is available to web agents.

I apologize for my hurried initial reply.

Chris