Permission denied to call method XMLHttpRequest.open in jQuery

Introduction

I received below error message in firebug when i try to use jQuery Ajax call

var html = $.ajax({
url: "http://www.xxx.com",
async: false}).responseText;

 Where http://www.xxx.com is different domain from my current site.

Exception... "'Permission denied to call method XMLHttpRequest.open' when calling method: [nsIDOMEventListener::handleEvent]" nsresult: "0x8057001e (NS_ERROR_XPC_JS_THREW_STRING)" location: "" data: no]

As far as my understanding, this is not allowed. In order to have the similar result, use Cross Domain getJSON or you can check on my sample in other post which work on cross domain ajax.

Ajax treat http://www.xxx.com and http://xxx.com as two different entry. There are different between url with www and without www. To solve this problem, use location.host to get the url that use by visitors.

Example

var html = $.ajax({
url: "http://"+location.host+ "/Realtime.ashx" + "?PostID=" + PostID,
async: false}).responseText; 

That's all, now problem in solved.Happy coding.