<script>
function changeCity(){
var province = document.getElementById("province").value;
var city = document.getElementById("city");
var citys = new Array();//申明一个一维数组
citys[0] = ["湖南","长沙","株洲","湘潭","永州"];//可看做是一个二维数组
citys[1] = ["广东","惠州","广州","中山"];
citys[2] = ["海南","海口","三亚","临高"];
city.length=0;//清空city下拉框中的值
for(var i=0; i<citys.length; i++){
if(province==citys[i][0])
{
for(var j=1; j<citys[i].length; j++){
var newOption = document.createElement("option");//创建一个option对象
newOption.value = citys[i][j];//给option赋值
newOption.text = citys[i][j];//这里表示option中间的那个值
city.add(newOption);//把创建的option对象添加到city下拉框中
}
}
}
}
</script>
省份:
<select id="province" onchange="changeCity()">
<option value="湖南">湖南</option>
<option value="广东">广东</option>
<option value="海南">海南</option>
</select>
城市:
<select id="city">
<option>长沙</option>
<option>株洲</option>
<option>湘潭</option>
</select>
