Function _ Javascript skills for javascript to obtain information such as the position of a scroll bar

Sometimes, in order to accurately locate an element, we need to obtain the position of the scroll bar. This requirement is often used in applications such as tooltip and drag-and-drop. In fact, this technology is very simple. The key is to consider browser compatibility, this article describes how to solve this problem. In fact, this Code has already been introduced in the previous article "using Javascript to achieve smooth jump between Anchor". However, this article is specially published on this site because this requirement is frequently used, easy to view.

The Code is as follows: