/**
     * 进入全屏
     */
    function requestFullScreen() 
    {
        var de = document.documentElement;
        if(de.requestFullscreen) 
        {
            de.requestFullscreen();
        } 
        else if(de.mozRequestFullScreen) 
        {
            de.mozRequestFullScreen();
        } 
        else if(de.webkitRequestFullScreen) 
        {
            de.webkitRequestFullScreen();
        }
    }
    
    /**
     * 退出全屏
     */
    function exitFullscreen()
    {
        var de = document;
    
        if (de.exitFullscreen) 
        {
            de.exitFullscreen();
        } 
        else if (de.mozCancelFullScreen) 
        {
            de.mozCancelFullScreen();
        } 
        else if (de.webkitCancelFullScreen) 
        {
            de.webkitCancelFullScreen();
        }
    }