window.onload = function () {

    initScreenSaver();

}

//0912 add

function ScreenSaver(settings){     

    this.settings = settings;     

    this.nTimeout = this.settings.timeout;     

    document.body.screenSaver = this;

    // link in to body events

    document.body.onmousemove = ScreenSaver.prototype.onevent;

    document.body.onmousedown = ScreenSaver.prototype.onevent;

    document.body.onkeydown = ScreenSaver.prototype.onevent;

    document.body.onkeypress = ScreenSaver.prototype.onevent;     

    var pThis = this;

    var f = function(){pThis.timeout();}

    this.timerID = window.setTimeout(f, this.nTimeout);

}

ScreenSaver.prototype.timeout = function(){

   if ( !this.saver ){

      window.history.back(-1)//无动作跳转地址

   }

}

ScreenSaver.prototype.signal = function(){

   if ( this.saver ){

      this.saver.stop();

   }     

   window.clearTimeout(this.timerID);     

   var pThis = this;

   var f = function(){pThis.timeout();}

   this.timerID = window.setTimeout(f, this.nTimeout);

}     

ScreenSaver.prototype.onevent = function(e){

   this.screenSaver.signal();

}     

var saver;

function initScreenSaver(){

   saver = new ScreenSaver({timeout:20000});   //无动作时间

}