've run into a snag and all the books I've consulted are of no help whatsoever.

I have 6 GIF files that I want to combine into an animated web banner. I know, I know, use layers! But, how in the heck do you get those GIFs onto the layers???

I can open the layers pallete and then open one of my GIFs. The pallette then shows that one GIF. But it will not accept any more and everything to do with layers is grayed out. I know I'm missing something and there must be some way to get each GIFF onto a separate layer and displayed in the layers pallette, but for the life of me I cannot figure it out. Thanks for any help or guidance in this area. I'm totally lost.