Change inactive page 'Title'

Question

I influenced from StackOverflow Chat.
Here when the page is inactive then number of the new incoming chat messages are displayed in the Page title. When the page is activated the this number is disappeared. How can I implement this concept in my application? I also want to highlight that window.

Answer 1

detecting when it goes inactive can be done with 'window.onblur' (the onblur event)

detecting when it goes active again can be done with 'window.onfocus' (the onfocus event)