Change top window location from iframe

Hello I want to redirect my Facebook App page to another app page using php and javascript

I have

echo "<script type='text/javascript'>
if(window.top.location.href.toLowerCase().indexOf('http://apps.facebook.com/app1/') != -1) {
    window.top.location.href = 'http://apps.facebook.com/app2/2/';
    alert("Done");
}
else
   alert(window.top.location.href); 
</script>";

But I get an error:

Unsafe JavaScript attempt to开发者_StackOverflow社区 access frame with URL http://apps.facebook.com/myapp/?ref=bookmarks from frame with URL http://mydomain.com/?ref=bookmarks. Domains, protocols and ports must match.

Is it possible to redirect from the Facebook Application iFrame without any problem?

due to XSS-resrictions you can set but cannot read top.location.href if your iframe resides on another domain than the page that calls the iframe. If the page you are redirecting to has the same domainname you will be able to check top.location.href. So the logic if your code should be reversed checking if it can access top.location.href and if NOT redirect. put it in a try..catch block to avoid javascript errors when accessing top.location