先来看看效果：

Html源码：

动态改变菜单

Javascript源码

$(document).ready(function () {

//找到三个下拉框

var ProvinceSelect = $(".Province").children("select");

var CitySelect = $(".City").children("select");

var AreaSelect = $(".Area").children("select");

var AddressSelect=$(".AddressSelect");

//给第二个下拉框注册事件

ProvinceSelect.change(function () {

//1、获取当前下拉框的值

var ProvinceValue = $(this).val();

//1.1只要第一个下拉框内容有变化，第三个下拉框就要隐藏起来

AreaSelect.parent().hide();

AddressSelect.hide();

AddressSelect.html("");

//2、如果值不为空，则显示城市下拉框

if (ProvinceValue != "") {

CitySelect.html("");

$("Please Choose City").appendTo(CitySelect);

switch(ProvinceValue)

{

//实际项目中，这个城市数组肯定是在服务器获取的，这里为了简便，我就直接自定义了一个数组

//如果追求完美，这里还可以加一道缓存，防止重复获取

case "HeBei":

var CityOfHeBei=["ShiJiaZhuang","CangZhou","LangFang"];

for(var i=0;i

$(""+CityOfHeBei[i]+"").appendTo(CitySelect);

}

break;

case "ShanDong":

var CityOfShanDon=["JiNan","DeZhou","QingDao"];

for(var i=0;i

$(""+CityOfShanDon[i]+"").appendTo(CitySelect);

}

break;

}

CitySelect.parent().show();

} else {

CitySelect.parent().hide();

}

});

//给第二个下拉框注册事件

CitySelect.change(function () {

var CityValue = $(this).val();

AddressSelect.hide();

AreaSelect.parent().hide();

AddressSelect.html("");

if (CityValue != "") {

AreaSelect.html("");

$("Please Choose Area").appendTo(AreaSelect);

switch(CityValue)

{

//实际项目中，这个区数组肯定是在服务器获取的，这里为了简便，我就直接自定义了一个数组

//如果追求完美，这里还可以加一道缓存，防止重复获取

case "ShiJiaZhuang":

var AreaOfCity=["GaoXinQu","KaiFaQu","XinHuaQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

case "CangZhou":

var AreaOfCity=["XinHuaQu","YunHeQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

case "LangFang":

var AreaOfCity=["AnCiQu","GuangYangQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

case "QingDao":

var AreaOfCity=["GaoXinQu","KaiFaQu","XinHuaQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

case "DeZhou":

var AreaOfCity=["XinHuaQu","YunHeQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

case "JiNan":

var AreaOfCity=["AnCiQu","GuangYangQu"];

for(var i=0;i

$(""+AreaOfCity[i]+"").appendTo(AreaSelect);

}

break;

}

AreaSelect.parent().show();

} else {

AreaSelect.parent().hide();

}

});

AreaSelect.change(function(){

var AreaValue=$(this).val();

AddressSelect.html("");

if (AreaValue!=""){

$("The Address Is --Province: "+ProvinceSelect.val()+"  City: "+CitySelect.val()+"  Area: "+AreaSelect.val()+"").appendTo(AddressSelect);

AddressSelect.show();

//alert("The Address Is  Province: "+ProvinceSelect.val()+"  City: "+CitySelect.val()+"  Area: "+AreaSelect.val());

}

})

});

这里还引用了Jquery，貌似实现这个效果，用不用都无所谓，最近为了熟悉Jquery的用法，所以就加上了。