简单的例子:http://www.longtailvideo.com/blog/26517/using-the-browsers-new-html5-fullscreen-capabilities/

<script type="text/javascript">
  function goFullscreen(id) {
    // Get the element that we want to take into fullscreen mode
    var element = document.getElementById(id);

    // These function will not exist in the browsers that don't support fullscreen mode yet, 
    // so we'll have to check to see if they're available before calling them.

    if (element.mozRequestFullScreen) {
      // This is how to go into fullscren mode in Firefox
      // Note the "moz" prefix, which is short for Mozilla.
      element.mozRequestFullScreen();
    } else if (element.webkitRequestFullScreen) {
      // This is how to go into fullscreen mode in Chrome and Safari
      // Both of those browsers are based on the Webkit project, hence the same prefix.
      element.webkitRequestFullScreen();
   }
   // Hooray, now we're in fullscreen mode!
  }
</script>

<img class="video_player" src="image.jpg" id="player"></img>
<button onclick="goFullscreen('player'); return false">Click Me To Go Fullscreen! (For real)</button>

在较新的浏览器中，如Chrome 15, Firefox 10, Safari 5.1, IE 10，这是可能的。根据浏览器设置，旧版本的IE也可以通过ActiveX实现。

以下是如何做到这一点:

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);

用户显然需要首先接受全屏请求，并且不可能在页面加载时自动触发此请求，它需要由用户触发(例如。一个按钮)

阅读更多信息:https://developer.mozilla.org/en/DOM/Using_full-screen_mode

简单的例子:http://www.longtailvideo.com/blog/26517/using-the-browsers-new-html5-fullscreen-capabilities/

<script type="text/javascript">
  function goFullscreen(id) {
    // Get the element that we want to take into fullscreen mode
    var element = document.getElementById(id);

    // These function will not exist in the browsers that don't support fullscreen mode yet, 
    // so we'll have to check to see if they're available before calling them.

    if (element.mozRequestFullScreen) {
      // This is how to go into fullscren mode in Firefox
      // Note the "moz" prefix, which is short for Mozilla.
      element.mozRequestFullScreen();
    } else if (element.webkitRequestFullScreen) {
      // This is how to go into fullscreen mode in Chrome and Safari
      // Both of those browsers are based on the Webkit project, hence the same prefix.
      element.webkitRequestFullScreen();
   }
   // Hooray, now we're in fullscreen mode!
  }
</script>

<img class="video_player" src="image.jpg" id="player"></img>
<button onclick="goFullscreen('player'); return false">Click Me To Go Fullscreen! (For real)</button>

新的html5技术-全屏API给了我们一个简单的方法 以全屏模式显示网页内容。我们即将付出 全屏模式的详细信息。试着 想象一下你可以利用它得到的所有可能的好处 技术-全屏相册，视频，甚至游戏。

但在我们描述这项新技术之前，我必须指出，这项技术是实验性的，所有主流浏览器都支持它。

你可以在这里找到完整的教程:http://www.css-jquery-design.com/2013/11/javascript-jquery-fullscreen-browser-window-html5-technology/

这里是工作演示:http://demo.web3designs.com/javascript-jquery-fullscreen-browser-window-html5-technology.htm

这是JavaScript中最接近全屏的效果:

<script type="text/javascript">
    window.onload = maxWindow;

    function maxWindow() {
        window.moveTo(0, 0);

        if (document.all) {
            top.window.resizeTo(screen.availWidth, screen.availHeight);
        }

        else if (document.layers || document.getElementById) {
            if (top.window.outerHeight < screen.availHeight || top.window.outerWidth < screen.availWidth) {
                top.window.outerHeight = screen.availHeight;
                top.window.outerWidth = screen.availWidth;
            }
        }
    }
</script> 

以下是我对全屏和退出全屏的完整解决方案(非常感谢上面塔的回答):

$(document).ready(function(){
$.is_fs = false;
$.requestFullScreen = function(calr)
{
    var element = document.body;

    // 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}");
        }
    }

    $.is_fs = true;    
    $(calr).val('Exit Full Screen');
}

$.cancel_fs = function(calr)
{
    var element = document; //and NOT document.body!!
    var requestMethod = element.exitFullScreen || element.mozCancelFullScreen || element.webkitExitFullScreen || element.mozExitFullScreen || element.msExitFullScreen || element.webkitCancelFullScreen;

    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}");
        }
    }    

    $(calr).val('Full Screen');    
    $.is_fs = false;
}

$.toggleFS = function(calr)
{    
    $.is_fs == true? $.cancel_fs(calr):$.requestFullScreen(calr);
}

});

// 调用:

<input type="button" value="Full Screen" onclick="$.toggleFS(this);" />