initialize()

initialize(){

  ...

  loaddata(){

    ...

    showdays(){

      ...show the controll panel and change the number of the list of place when days changed.

    }

  }

}

onclick

sendRequire(){

  ...

  request.open("GET", "servlet/gmap?action=match&budget=" + budget + "&peoples=" + peoples + "&requirement=" + requirement, true);

  tripresult(){

    ...

  }

}

onchange

setPreEnd(){

  ...created by showdays using innerHTML

  ...let i-1 day's endat = i day's stfrom(startfrom)

  calcRoute(){ //also directly called by list of places 

    ...

    changecity() : change the format of city to what google map needs

    directionsService.route() : google map's function

  }

}

onchange

showPackage(){

  ...

  

}