Question

I have this function

function getSwf(appName) {
    if (navigator.appName.indexOf("Microsoft") != -1)
        return window[appName];
    return document[appName];
}

But not sure if the last 2 lines are correct. I mean,

        return window[appName];
    return document[appName];

or

        return document[appName];
    return window[appName];

Answer 1

If you’re trying to find a global variable, it’s always on window.

If you’re trying to find an HTML element with an id, on most browsers, it’s always on window, but that behavior isn’t (yet) the subject of an active specification; to be really sure, use document.getElementById(appName) instead, which will work on all browsers. (Firefox, for instance, doesn’t put elements with ids on window.)

IE will also tend to throw elements with names on window, even though name values aren’t required to be unique. sigh Other browsers, thankfully, don’t.