function requestFullScreen(element) {
    // Supports most browsers and their versions.
    var requestMethod = element.requestFullScreen || element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen;

    if (requestMethod) { // Native full screen.
        requestMethod.call(element);
    } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
        var wscript = new ActiveXObject("WScript.Shell");
        if (wscript !== null) {
            wscript.SendKeys("{F11}");
        }
    }
}

var elem = document.body; // Make the body go full screen.
requestFullScreen(elem);