函数window.open实现关闭所有的子窗口

function closeSonWindow(win){
  for(var index=0;index<win.length;index++){
    //如果窗口已关闭
    if(win[index].closed){
      continue;
    }
    //如果窗口没有可以打开的子窗口
    if(typeof(win[index].openedWindow)=="undefined"){
      win[index].close();
      continue;
    }
    if(win[index].openedWindow.length==0){
      win[index].close();
    }else{
      closeSonWindow(win[index].openedWindow);
      win[index].close();
    }
  }
}