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Firefox 10中，你可以使用以下javascript使当前页面全屏(没有窗口chrome的真正全屏):

window.fullScreen = true;

这个函数非常好用

function toggle_full_screen()
{
    if ((document.fullScreenElement && document.fullScreenElement !== null) || (!document.mozFullScreen && !document.webkitIsFullScreen))
    {
        if (document.documentElement.requestFullScreen){
            document.documentElement.requestFullScreen();
        }
        else if (document.documentElement.mozRequestFullScreen){ /* Firefox */
            document.documentElement.mozRequestFullScreen();
        }
        else if (document.documentElement.webkitRequestFullScreen){   /* Chrome, Safari & Opera */
            document.documentElement.webkitRequestFullScreen(Element.ALLOW_KEYBOARD_INPUT);
        }
        else if (document.msRequestFullscreen){ /* IE/Edge */
            document.documentElement.msRequestFullscreen();
        }
    }
    else
    {
        if (document.cancelFullScreen){
            document.cancelFullScreen();
        }
        else if (document.mozCancelFullScreen){ /* Firefox */
            document.mozCancelFullScreen();
        }
        else if (document.webkitCancelFullScreen){   /* Chrome, Safari and Opera */
            document.webkitCancelFullScreen();
        }
        else if (document.msExitFullscreen){ /* IE/Edge */
            document.msExitFullscreen();
        }
    }
}

要使用它，只需调用:

toggle_full_screen();

这将在全屏显示你的窗口

注意:要使其工作，您需要来自http://code.jquery.com/jquery-2.1.1.min.js的Query

或者让javascript链接像这样。

<script src="http://code.jquery.com/jquery-2.1.1.min.js"></script>

   <div id="demo-element">
        <span>Full Screen Mode Disabled</span>
        <button id="go-button">Enable Full Screen</button>
    </div>
    <script>
    function GoInFullscreen(element) {
        if(element.requestFullscreen)
            element.requestFullscreen();
        else if(element.mozRequestFullScreen)
            element.mozRequestFullScreen();
        else if(element.webkitRequestFullscreen)
            element.webkitRequestFullscreen();
        else if(element.msRequestFullscreen)
            element.msRequestFullscreen();
    }

    function GoOutFullscreen() {
        if(document.exitFullscreen)
            document.exitFullscreen();
        else if(document.mozCancelFullScreen)
            document.mozCancelFullScreen();
        else if(document.webkitExitFullscreen)
            document.webkitExitFullscreen();
        else if(document.msExitFullscreen)
            document.msExitFullscreen();
    }

    function IsFullScreenCurrently() {
        var full_screen_element = document.fullscreenElement || document.webkitFullscreenElement || document.mozFullScreenElement || document.msFullscreenElement || null;

        if(full_screen_element === null)
            return false;
        else
            return true;
    }

    $("#go-button").on('click', function() {
        if(IsFullScreenCurrently())
            GoOutFullscreen();
        else
            GoInFullscreen($("#demo-element").get(0));
    });

    $(document).on('fullscreenchange webkitfullscreenchange mozfullscreenchange MSFullscreenChange', function() {
        if(IsFullScreenCurrently()) {
            $("#demo-element span").text('Full Screen Mode Enabled');
            $("#go-button").text('Disable Full Screen');
        }
        else {
            $("#demo-element span").text('Full Screen Mode Disabled');
            $("#go-button").text('Enable Full Screen');
        }
    });</script>

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> 

函数f () {plr.requestFullscreen (); document.exitFullscreen ()};plr.requestFullscreen():document.exitFullscreen()}

<!DOCTYPE html><html><head>

<style>
body{background:#000}
#plr{position:relative;background:#fff;width:360px}
#vd{width:100%;background:grey}
button{width:48px;height:48px;border:0;background:grey}
</style>

</head><body>

<div id="plr">
<video id="vd" src="video.mp4"></video>
<button onclick="(plr.offsetWidth==360)?plr.requestFullscreen():document.exitFullscreen()">fs</button>
<button onclick="plr.requestFullscreen();document.exitFullscreen()">fs2</button>
</div>

</body></html>