National provinces and cities two-level linkage drop-down Menu JS version _javascript skills

This example for you to share the JS implementation of the two-level linkage drop-down menu specific code for your reference, the specific content as follows

JS Code section:

* * National level Two City linkage JS version */function Dsy () {this.
Items = {}; } Dsy.prototype.add = function (Id,iarray) {this.
Items[id] = IArray; } Dsy.prototype.Exists = function (id) {if typeof (this.
  Items[id] = = "undefined") return false;
return true;
  function Change (v) {var str= "0";
  for (i=0;i<v;i++) {str+= ("_" + (document.getElementById (s[i)). selectedIndex-1));
  };
  var Ss=document.getelementbyid (S[v]);
    With (ss) {length = 0;
    Options[0]=new Option (Opt0[v],opt0[v]); if (v && document.getElementById (S[v-1)). selectedindex>0 | |!v) {if (dsy. Exists (str)) {AR = Dsy.
        ITEMS[STR];
        for (i=0;i<ar.length;i++) {options[length]=new Option (ar[i],ar[i]);
      }//end for if (v) {options[0].selected = true;}
  }}//end if v if (++v<s.length) {change (v);}

}//end with} var dsy = new Dsy (); Dsy.add ("0", ["Beijing", "Tianjin", "Shanghai City", "Chongqing City", "Hebei province," Shanxi province "," Inner Mongolia "," Liaoning province "," Jilin Province "," Heilongjiang province "," Jiangsu province "," Zhejiang province "," Anhui province "," Fujian province "," Jiangxi province "," Shandong province ", "Henan Province", "Hubei province", "Hunan province", "Guangdong province"," Guangxi "," Hainan Province "," Sichuan province "," Guizhou province "," Yunnan province "," Tibet "," Shaanxi province "," Gansu province "," Qinghai province "," Ningxia "," Xinjiang "," Hong Kong "," Macao "," Taiwan Province "]; Dsy.add ("0_0", ["Dongcheng District", "] Xicheng, Chongwen District, Xuanwu District, Chaoyang District, Fengtai District, Shijingshan, Haidian District, Tongzhou District," Shunyi District "," Changping District "," Daxing District "," Huairou ",", "".
Pinggu District "," Miyun County "," Yanqing County "," Yanqing Town "]; Dsy.add ("0_1", ["Zone of Peace"] Hedong District "," Hexi District "," Nankai District "," Hebei District "," Hongqiao District "," Tanggu District "," Hangu District "," Grand Port District "," Dongli District "," Xiqing District "," Jinnan District "," Beichen District "," Wuqing District "," Baochi District "," Jixian ",
"Ninghe County", "Qiangtai", "Jinghai County", "Jinghai Town"]; Dsy.add ("0_2", ["Huangpu District", "] Luwan District", "Xuhui District", "Changning area", "Jingan", "Putuo", "Zhabei", "Hongkou", "Yangpu", "Minhang", "Baoshan ", "Jiading", "Pudong", "Jinshan", "Songjiang", "
Qingpu "," Nanhui "," Fengxian "," Chongming County "," Town Bridge "]; Dsy.add ("0_3", ["Yuzhong District", "Dadukou District", "Jiangbei District", "Shapingba District", "Jiulongpo District", "Nanan District", "Beibei", "Wancheng District", "Shuangqiao District", "Yubei District", "Banan", "Wanxian District", "Fuling District", "Qianjiang District", "Changshou District", " Hechuan "," Yongchuan District City "," Jiangjin "," Nanchuan "," Qijiang County "," Tongnan County "," Tongliang County "," Dazu County "," Rongchang County "," Bishan County "," Dianjiang County "," Wulong County "," Fengdou County "," Chengkou County "," Liangping County "," Kai "," Wuxi County "," Wushan County ","
Fengjie County "," Yunyang County "," Zhongxian "," Shizhu County "," Pengshui County "," Youyang County "," Xiushan County "];
Dsy.add ("0_4", "Shijiazhuang City", "Zhangjiakou City", "Chengde", "Qinhuangdao Shi", "Tangshan", "Langfang", "Baoding", "Hengshui", "Cangzhou", "Xingtai", "Hanhan"]);
Dsy.add ("0_5", ["Taiyuan City", "Shuozhou," "Datong", "Yangquan", "Changzhi", "Jincheng", "Xinzhou", "Jinzhong", "Linfen", "Luliang City", "Yun City"]); Dsy.add ("0_6", ["Hohhot City", "Baotou", "Wuhai", "Chifeng", "Tongliao", "shoutLember City "," Eerduosi "," Wulanchabu City "," Bayan nur City "," Hinggan League "," the Xilin Gol League "," Alashan "]);
Dsy.add ("0_7", ["Shenyang City", "] Chaoyang", "Fuxin", "Tieling", "Fushun", "Benxi", "Liaoyang", "Anshan", "Dandong", "Dalian", "Yingkou", "Panjin", "Jinzhou", "Huludao"];
Dsy.add ("0_8", ["Changchun", "White City", "Songyuan", "Jilin", "Siping", "Liaoyuan", "Tonghua", "Bss", "Yanbian State"]);
Dsy.add ("0_9", ["Harbin City", "Qiqihar", "Qitaihe Shi", "Heihe", "Daqing", "Hegang", "Yichun", "Jiamusi", "Shuangyashan", "Jixi", "Mudanjiang", "Suihua", "daxinganling"]);
Dsy.add ("0_10", ["Nanjing", "Xuzhou", "Lianyungang", "Suqian", "Huaian", "Yancheng", "Yangzhou", "Taizhou", "Nantong", "Zhenjiang", "Changzhou", "Wuxi", "Suzhou"]);
Dsy.add ("0_11", ["Hangzhou City", "Huzhou", "Jiaxing", "Zhoushan", "Ningbo", "Shaoxing", "Quzhou", "Jinhua", "Taizhou", "Wenzhou", "Lishui"]); Dsy.add ("0_12", ["Hefei", "Suzhou", "Huaibei", "Bozhou", "Fuyang", "Bangbu", "Huainan", "Chuzhou", "Maanshan", "Wuhu", "Tongling", "Anqing", "Huangshan", "Liu'an", "Chaohu", "
Chizhou "," Xuancheng "]);
Dsy.add ("0_13", ["Fuzhou", "Nanping", "Putian", "Sanming", "Quanzhou", "Xiamen", "Zhangzhou", "Longyan", "Ningde"]);
Dsy.add ("0_14", ["Nanchang", "Jiujiang", "Jingdezhen", "Yingtan", "Xinyu", "Pingxiang", "Ganzhou", "Shangrao", "Fuzhou", "Yichun", "Jian"]); Dsy.add ("0_15", ["Jinan", "Qingdao", "Liaocheng", "Dezhou", "Dongying", "Zibo", "Weifang", "Yantai", "Weihai", "Rizhao", "Linyi", "Zaozhuang", "Jining", "Taian", "Laiwu", "Binzhou
"," Heze "]); Dsy.add ("0_16", ["Zhengzhou", "Kaifeng", "Sanmenxia Shi", "Luoyang", "Jiaozuo", "Xinxiang", "Hebi", "Anyang", "Puyang", "Shangqiu", "XuchangCity "," Leihe "," Pingdingshan "," Nanyang "," Xinyang "," Zhoukou "," Zhumadian "," Jiyuan "]);
Dsy.add ("0_17", ["Wuhan City", "] Shiyan", "Xiangfan", "Jingmen", "Xiaogan", "Huanggang", "Ezhou", "Huangshi", "Xianning", "Jinzhou", "Yichang", "Suizhou", "Provincial Crown County Administrative Unit", "Enshi Autonomous Prefecture"]);
Dsy.add ("0_18", ["Changsha", "Zhangjiajie", "Changde", "Yiyang", "Yueyang", "Zhuzhou", "Xiangtan", "Hengyang", "Chenzhou", "Yongzhou", "Shaoyang", "Huaihua", "Loudi", "Xiangxi State"]); Dsy.add ("0_19", ["Guangzhou", "Shenzhen", "Qingyuan", "Shaoguan", "Heyuan", "Meizhou", "Chaozhou", "Shantou", "Jieyang", "Shanwei", "Huizhou", "Dongguan", "Zhuhai", "Zhongshan", "Jiangmen", "Foshan
"," Zhaoqing "," Yunfu "," Yangjiang "," Maoming "," Zhanjiang "];
Dsy.add ("0_20", ["Nanning", "Guilin", "Liuzhou", "Wuzhou", "Guigang", "Yulin", "Qinzhou", "Beihai", "Fangchenggang", "Chongzuo City", "Baise", "Hechi", "Guest City", "Hezhou"];
Dsy.add ("0_21", ["Haikou", "Sanya", "Provincial Crown Administrative Unit"]); Dsy.add ("0_22", ["Chengdu City", "] Guangyuan", "Mianyang", "Deyang", "Nanchong", "Guangan", "Suining", "Neijiang", "Leshan", "Zigong", "Luzhou", "Yibin", "Panzhihua", "Bazhong", "Dazhou", "
Ziyang "," Meishan "," Yaan "," ABA "," Ganzi State "," Liangshan prefecture "];
Dsy.add ("0_23", ["Guiyang", "Liupanshui", "Zunyi", "Anshun", "Bijie Prefecture", "Tongren Prefecture", "Qiandongnan", "Qiannan", "Southwestern Guizhou"]); Dsy.add ("0_24", ["Kunming", "Qujing", "Yuxi", "Baoshan", "Zhaotong", "Lijiang City", "Simao", "Lincang City", "Dehong", "Nu River State", "Diqing", "Dali Prefecture", "Chuxiong Prefecture", "Honghe", "Wenshan", "
Xishuangbanna State "]);
Dsy.add ("0_25", ["Lasa", "Nagchu", "Changdu", "Linzhi", "Shannan", "Xigazê", "Ali"]); Dsy.add ("0_26", ["Xi ' an city", "Yanan", "Tongchuan", "Weinan"," Xianyang "," Baoji "," Hanzhong "," Yulin "," Ankang "," Shangluo "];
Dsy.add ("0_27", "Lanzhou City", "Jiayuguan", "Baiyin", "Tianshui", "Wuwei", "Jiuquan", "Zhangye", "Qingyang City", "Pingliang", "Dingxi City", "Longnan", "Linxia State", "Gannan State"];
Dsy.add ("0_28", ["Xining City", "Haidong Prefecture", "Haibeizhou", "Hainan State", "Huangnan State", "Guo Luo state", "Yushu", "Haixizhou"]);
Dsy.add ("0_29", ["Yinchuan", "Shizuishan", "Wuzhong", "Guyuan", "Zhongwei City"]); Dsy.add ("0_30", ["Urumqi", "Karamay", "Autonomous prefecture-level administrative unit", "Kashi", "Aksu region", "Hotan Prefecture", "Turpan", "Hami", "Suko", "Bortala State", "Changji state", "
Bayin Guo Len State "," Ili state "," Tacheng Prefecture "," Altay "];
Dsy.add ("0_31", ["Hong Kong Special Administrative Region"]);
Dsy.add ("0_32", ["Macao Special Administrative Region"]); Dsy.add ("0_33", "Taipei", "Kaohsiung", "Taichung", "Hualian"), "Keelung," Chiayi "," Kinmen "," Lianjiang "," Miaoli "," Nantou "," Penghu "," Pingdong "," Taitung "," Tainan "," Taoyuan "," Hsinchu "," Yilan "," Yunlin "," Changhua "
]); Dsy.add ("0", ["Beijing", "Tianjin", "Shanghai City", "Chongqing City", "Hebei province," Shanxi province "," Inner Mongolia "," Liaoning province "," Jilin Province "," Heilongjiang province "," Jiangsu province "," Zhejiang province "," Anhui province "," Fujian province "," Jiangxi province "," Shandong province ",

"Henan Province", "Hubei province", "Hunan province", "Guangdong province", "Guangxi", "Hainan Province", "Sichuan province", "Guizhou province", "Yunnan province", "Tibet", "Shaanxi province", "Gansu province", "Qinghai province", "Ningxia", "Xinjiang", "Hong Kong", "Macao", "Taiwan Province"]; var s=["S_province", "s_city"];//three select name var opt0 = ["Province", "prefecture-level"];//Initial value function _init_area () {//initialization function for (i=0;i&lt
 s.length-1;i++) {document.getElementById (S[i]). Onchange=new Function ("Change (" + (i+1) +) "); Change (0);
 }

HTML code section:

The above is the entire content of this article, I hope to help you learn.