[aprssig] Flashing GIF

[Robert Bruninga]

Can someone tell me how to make a flashing JPG or GIF?

On my LOCALINFO web page I am showing the screen of a D7 with
the "MY MESSAGE" showing that it was digipeated.  I'd like to
make that image FLASH the MY MESSAGE just like it does for
real...

I assume I just make a copy of the image with and without the
message, but then how do I save them so that they alternate?

Thanks
Bob WB4APR