城市二级联动

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title> New Document </title>
<script language="JavaScript" type="text/javascript">
<!--
//按照省份下拉列表框的顺序定义二维数组,将城市列表对应到省份
var city=[
 ["北京","天津","上海","重庆"],  //直辖市
 ["南京","苏州","南通","常州"],  //江苏省
 ["福州","福安","龙岩","南平"],  //福建省
 ["广州","潮阳","潮州","澄海"],  //广东省
 ["兰州","白银","定西","敦煌"]  //甘肃省
];

function getCity(){
 //获得身省份和城市下拉列表框的引用
 var sltProvince=document.forms["theForm"].elements["province"];
 var sltCity=document.forms["theForm"].elements["city"];
 //得到对应于省份的城市列表数组
 var provinceCity=city[sltProvince.selectedIndex-1];
 
 //将城市下拉列表框清空,仅留第一个提示选项
 sltCity.length=1;
 //将相应省市的城市填充到城市选择框中
 for(var i=0;i<provinceCity.length;i++){
  //创建新的Option对象并将其添加到城市下拉列表框中
  sltCity[i+1]=new Option(provinceCity[i],provinceCity[i]);
 }
}
//-->
</script>
</head>
<body>

<form action="somepage.asp" name="theForm">
<select name="province" onchange="getCity()">
 <option value="0">请选择所在省份</option>
 <option value="直辖市">直辖市</option>
 <option value="江苏省">江苏省</option>
 <option value="福建省">福建省</option>
 <option value="广东省">广东省</option>
 <option value="甘肃省">甘肃省</option>
</select>
<select name="city">
 <option value="0">请选择所在城市</option>
</select>
</form>
</body>
</html>
原文地址:https://www.cnblogs.com/yaomin/p/6424955.html