如何全屏显示整个网页并禁用f11和ESC按钮？

<style>
    html, body {
        margin: 0;
        padding: 0;
        overflow: hidden;
    }
</style>

<script>
    // 禁用F11按钮
    document.onkeydown = function (event) {
        if (event.keyCode == 122) {
            event.preventDefault();
        }
    };

    // 禁用ESC按钮
    document.onkeyup = function (event) {
        if (event.keyCode == 27) {
            event.preventDefault();
        }
    };

    // 全屏显示网页
    function toggleFullScreen() {
        if (!document.fullscreenElement &&    // 不在全屏模式下
            !document.mozFullScreenElement && !document.webkitFullscreenElement && !document.msFullscreenElement) {  // 兼容不同浏览器
            if (document.documentElement.requestFullscreen) {
                document.documentElement.requestFullscreen();
            } else if (document.documentElement.mozRequestFullScreen) {
                document.documentElement.mozRequestFullScreen();
            } else if (document.documentElement.webkitRequestFullscreen) {
                document.documentElement.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
            } else if (document.documentElement.msRequestFullscreen) {
                document.documentElement.msRequestFullscreen();
            }
        } else {
            if (document.exitFullscreen) {
                document.exitFullscreen();
            } else if (document.mozCancelFullScreen) {
                document.mozCancelFullScreen();
            } else if (document.webkitExitFullscreen) {
                document.webkitExitFullscreen();
            } else if (document.msExitFullscreen) {
                document.msExitFullscreen();
            }
        }
    }
</script>

<button onclick="toggleFullScreen()">全屏显示</button>