<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script language="JavaScript" type="text/javascript">
var cityArr = [];
cityArr['江苏省'] = [{txt:'南京', val:'南京'},
{txt:'无锡', val:'无锡'},
{txt:'徐州', val:'徐州'},
{txt:'苏州', val:'苏州'},
{txt:'南通', val:'南通'},
{txt:'淮阴', val:'淮阴'},
{txt:'扬州', val:'扬州'},
{txt:'镇江', val:'镇江'},
{txt:'常州', val:'常州'}];
cityArr['浙江省'] = [{txt:'杭州', val:'杭州'},
{txt:'宁波', val:'宁波'},
{txt:'温州', val:'温州'},
{txt:'湖州', val:'湖州'}];
function removeOptions(selectObj)
{
if (typeof selectObj != 'object')
{
selectObj = document.getElementById(selectObj);
}
// 原有选项计数
var len = selectObj.options.length;
for (var i=0; i < len; i++)
{
// 移除当前选项
selectObj.options[0] = null;
}
}
/*
* 说明:设置传入的选项值到指定的下拉列表中
*
* @param {String || Object]} selectObj 目标下拉选框的名称或对象,必须
* @param {Array} optionList 选项值设置 格式:[{txt:'北京', val:'010'}, {txt:'上海', val:'020'}] ,必须
* @param {String} firstOption 第一个选项值,如:"请选择",可选,值为空
* @param {String} selected 默认选中值,可选
*/
function setSelectOption(selectObj, optionList, firstOption, selected)
{
if (typeof selectObj != 'object')
{
selectObj = document.getElementById(selectObj);
}
// 清空选项
removeOptions(selectObj);
// 选项计数
var start = 0;
// 如果需要添加第一个选项
if (firstOption)
{
selectObj.options[0] = new Option(firstOption, '');
// 选项计数从 1 开始
start ++;
}
var len = optionList.length;
for (var i=0; i < len; i++)
{
// 设置 option
selectObj.options[start] = new Option(optionList[i].txt, optionList[i].val);
// 选中项
if(selected == optionList[i].val)
{
selectObj.options[start].selected = true;
}
// 计数加 1
start ++;
}
}
function setCity(province) {setSelectOption('city', cityArr[province], '-请选择-'); }
</script>
<title>无标题文档</title>
</head>
<body>
<select name="province" id="province" onchange="if(this.value != '') setCity(this.options[this.selectedIndex].value);">
<option value="">-请选择-</option>
<option value="江苏省">江苏省</option>
<option value="浙江省">浙江省</option>
</select> 省
<select name="city" id="city">
<option value="">-请选择-</option> </select> 市
</body>
</html>