关于切换城市的资料网址：

http://bbs.51js.com/thread-81559-1-1.html

http://www.pyzy.net/Demo/js_city_and_date_v1/city_and_date.htm

http://bbs.51js.com/thread-76871-1-1.html

http://bbs.blueidea.com/thread-2983086-1-1.html

http://www.codefans.net/jscss/code/3202.shtml

http://bbs.blueidea.com/thread-3067942-1-1.html