Photo Gallery - adding previous & next button

Hi there,

I have a very nice picture gallery made in CS3 / AS3. I managed to personalize it and all. But, I have difficulty with (or no clue… actually), how to add a precious and next button to it(image).

This is the link for the zip file, containing all the neccesary files:

And in the attachment I pointed out where I prefer to have these two buttons.

Could anybody help me with this? It would be a valuable lesson :wink:
Thank you so much in advance!