Some questions regarding my project

[Tusike]

How can I get the two listboxes displaying the words and their paired meanings, to scroll together?

I tried using the MouseWheel event (even though VC didn't have that included in the listbox's "events" list, so I had to manually make it), and setting the two list's TopIndex to the same value there. But for some reason it didn't work, the two lists scrolled pretty much synchronously, but they were mostly off by 2-3 places.
I also manually made a TopIndexChanged event in the code, hoping it would exist as well, but that gave me an error.

EDIT: I ended up using a timer with 10 intervals, making sure the two TopIndex's agree each tick; it works just fine, although I'm not sure if it isn't "wasting" a lot of CPU time.