js实现全屏

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}");  
        }  
  }  
}