js设置浏览器全屏状态

        //判断屏幕是否全屏状态
        if(document.isFullScreen || document.mozIsFullScreen || document.webkitIsFullScreen == false){
            //设置全屏
            var el = document.documentElement;
            var rfs = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullscreen;      
            if(typeof rfs != "undefined" && rfs) {
                rfs.call(el);
            }
        }
        else{
            //退出全屏
            if (document.exitFullscreen) {  
                document.exitFullscreen();  
            }  
            else if (document.mozCancelFullScreen) {  
                document.mozCancelFullScreen();  
            }  
            else if (document.webkitCancelFullScreen) {  
                document.webkitCancelFullScreen();  
            }  
            else if (document.msExitFullscreen) {  
                document.msExitFullscreen();  
            } 
            if(typeof cfs != "undefined" && cfs) {
                cfs.call(el);
            }
        }