scroll bar   

There are two windows, they all have scroll bar and are irrespective.

In first window, when user drag the thumb, the window will receive
WM_VSCROLL message only when the ScrollInfo.nPos is changed 5 pixel;

But in second window, the window receive WM_VSCROLL message when the
ScrollInfo.nPos is changed 15 pixel.

The two window size and page size is same.

I can't find what cause this result. And I want to change the action in
first window, make it is same with the second.

Any one can help me?
Thanks a lot.

date: Thu, 24 Jul 2008 10:00:15 +0800   author:   Jerry New