scrolling image with limit

hi guys i'm going crazy to find a way to limit a scrolling image to fit its size, using the sample from ByaK@ called scrollimage..

well the main problem is if i block the top and left to 0 the will program crash

any easier method to limit the scroll just to the img size?

Let me know, any help will be much appreciated!

Thanks,
Europe

yes,i add new source to my topic)