A: 

It's just any URL that will always return back an HTTP 204 status code, indicating:

The server successfully processed the request, but is not returning any content.

Matt Ball
as you know this is for frame busting..So what should i put instead of "http://server-which-responds-with-204.com"...the url to which my page is redirecting to ??
5416339
Are you trying to write a frame buster? That code is part of a frame buster buster, e.g. it stops frame busters from working.
Matt Ball
var prevent_bust = 0window.onbeforeunload = function() { prevent_bust++ }setInterval(function() { if (prevent_bust > 0) { prevent_bust -= 2 window.top.location = 'http://mysite.com' }}, 1)
5416339
The problem is that it keeps redirecting to mysite..but i just want it to stop..what do i do ?
5416339
If you're trying to write a frame buster _buster_, whatever server you're using in place of `http://server-which-responds-with-204.com` _needs to always reply with an **HTTP 204** status code_. That means "No Content." That said, if people don't want you iframing their site, why not respect that?
Matt Ball
Well,I want to know the alternative :D
5416339