Why two scroll bar ?

[Gilles]

At the top of the list window, I noticed there is a small scroll bar.
If i extend it, i get two list windows:


what it is related to this?
Thank

[Kitty Hello]

Notice the very same thing on the left lower scoll bar? It's for spliting one source file. So you can have some comments you need all the time at the top of the code, split the window and type in the lower part, so you can have a quick look at the constants above.