JavaScript mouse events example This script has been written to create two functions, mouseOver () and mouseOut ().

JavaScript Event - Mouseover This code was written based on a template by John Resig. The original can be found at John Resig’s addEvent function website.

Some common tasks that can be performed using JavaScript relate to how the webpage responds to action taken by the user using their mouse or touchscreen. These are called mouse events.

A long-running [JavaScript] can lead to mouse events getting queued up on the main thread event queue. This results in janky scrolling to the end user.