javascript实现控制浏览器全屏

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}");    } }}