animated gifs

[Andrew]

Hello, everyone.  Could someone please lend me a hand with some advice 
for using animated gifs?
1. How do I stop a gif on a given frame? (such as when a button is 
pressed)
2. How do I flip a gif horizontally without losing the frame sequence?
3. How do I hide a currently playing gif and show a different gif, 
starting on a particular frame of the new gif?
(Are gifs still running even if they are hidden?  Does this consume 
memory?)

One more unrelated question:
I'm still having trouble with my "ask" window not appearing on my 
windows standalone due to something ill in my script, and the only 
suggestion that has been made is to replace "greater than or equals" 
signs with ">=".  I have done this, but windows still seems to find 
fault in my scripts, and it shows its disapproval by refusing to show 
my ask boxes.  Is there any other thing that I should replace in my 
scripts to appease windows?

Thanks a lot!
-Andrew