//id='content'需要放置在最外围的div中或者body中
<div id="content"></div>
 <button id='btn'>全屏按钮</button> //全屏按钮，没有点击的时候退出全屏按钮是不管用的。比如用F11全屏了，再点击退出全屏按钮就不管用。
 <button id="quite" class="btn">退出全屏</button>

<script type="text/javascript">
    var quite = document.getElementById('quite');
    quite.onclick = function(){
        exitFullScreen();
    }

    var btn = document.getElementById('btn');
    var content = document.getElementById('content');
    btn.onclick = function(){
        fullScreen(content);
    }
    function fullScreen(el) {
        var rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullScreen,
            wscript;
        if(typeof rfs != "undefined" && rfs) {
            rfs.call(el);
            return;
        }         

        if(typeof window.ActiveXObject != "undefined") {
            wscript = new ActiveXObject("WScript.Shell");
            if(wscript) {
                wscript.SendKeys("{F11}");
            }
        }
    }
function exitFullScreen(el) {
    var el= document,
        cfs = el.cancelFullScreen || el.webkitCancelFullScreen || el.mozCancelFullScreen || el.exitFullScreen,
        wscript;
    if (typeof cfs != "undefined" && cfs) {
      cfs.call(el);
      return;
    }
    if (typeof window.ActiveXObject != "undefined") {
        wscript = new ActiveXObject("WScript.Shell");
        if (wscript != null) {
            wscript.SendKeys("{F11}");
        }
    }
}

var fullscreen=function(){
    elem=document.body;
    if(elem.webkitRequestFullScreen){
        elem.webkitRequestFullScreen();   
    }else if(elem.mozRequestFullScreen){
        elem.mozRequestFullScreen();
    }else if(elem.requestFullScreen){
        elem.requestFullscreen();
    }else{
        //浏览器不支持全屏API或已被禁用
        elem.msRequestFullscreen();

    }
}
var exitFullscreen=function(){
    var elem=document;
    if(elem.webkitCancelFullScreen){
        elem.webkitCancelFullScreen();    
    }else if(elem.mozCancelFullScreen){
        elem.mozCancelFullScreen();
    }else if(elem.cancelFullScreen){
        elem.cancelFullScreen();
    }else if(elem.exitFullscreen){
        elem.exitFullscreen();
    }else{
     //浏览器不支持全屏API或已被禁用
     document.msExitFullscreen();
    }
}

function fullScreen() {

    var el = document.documentElement,

        rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullScreen,

        wscript;


    if(typeof rfs != "undefined" && rfs) {

        rfs.call(el);

        return;

    }


    if(typeof window.ActiveXObject != "undefined") {

        wscript = new ActiveXObject("WScript.Shell");

        if(wscript) {
            wscript.SendKeys("{F11}");
        }
    }

}


function exitFullScreen() {
    var el = document,
        cfs = el.cancelFullScreen || el.webkitCancelFullScreen || el.mozCancelFullScreen || el.exitFullScreen,

        wscript;

    if (typeof cfs != "undefined" && cfs) {
      cfs.call(el);
      return;
    }


    if (typeof window.ActiveXObject != "undefined") {
        wscript = new ActiveXObject("WScript.Shell");
        if (wscript != null) {
            wscript.SendKeys("{F11}");
        }
  }

}