web - What is the usage of javascript scrollTimeout? -

i encounter scrolltimeout , couldn't figure usage of it, can't find useful result in google too! isn't there refernece javascript functions ?

settimeout returns id, check see if still active , cancel it.

var onscrollvisitorsblock = function () {         cleartimeout(scrolltimeout);         scrolltimeout = settimeout(function () {         .... 

this way, function not continuously executing.