<p>I am writing an iframe based facebook app. Now I want to use the same html page to render the normal website as well as the canvas page within facebook. I want to know if I can determine whether the page has been loaded inside the iframe or directly in the browser?</p>

Browsers can block access to
```
window.top
```
due to
same origin policy
. IE bugs also take place. Here's the working code:
```
```
function inIframe () {
    try {
        return window.self !== window.top;
    } catch (e) {
        return true;
    }
}
```
```
```
top
```
and
```
self
```
are both
```
window
```
objects (along with
```
parent
```
), so you're seeing if your window is the top window.