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}");
    }
 }
}