Scratch

Yeah you probably should have been more specific but luckily for you, I've played Tiny Tower and I think I know what you're on about. Do you want to know how to do y scrolling like in the game? Basically, it's like x scrolling except wherever you see the number 480, replace it with 360. Here's an example.

For the first picture of the scrolling background:

forever
set x to (0)
set y to ((ScrollY)+([360] * [0]))

for the second scrolling picture;

forever
set x to (0)
set y to ((ScrollY)+([360] * [1]))//basically, change "1" to the picture number for each picture in the scroller

You also need to include this script:

forever
if <key [up arrow v] pressed ?>
change [ScrollY v] by [10]
end
if <key [down arrow v] pressed ?>
change [ScrollY v] by [-10]

For more info, see this wiki article.