／／依据所选的省。自己主动生成相应的市
<html>
<head>
<title>级联列表</title>
<meta http-equiv='Content-Type' content='text/css;charset=utf-8'/>
<style>
.yemian{
margin-left:30%;
text-align:center;
font-size:50px;
500px;
height:500px;
background-color:blue;
}
.s{
120px;
height:25px;
}
</style>
<script>
function st(){
var sheng=document.getElementById('sheng');
//存省的数组。可自行加入
var shengs=new Array(new Option("--请选择省--",''),new Option("湖南","hn"),new Option("广东","gd"));
for(var i=0;i<shengs.length;i++){
sheng.options[i]=shengs[i];
}
}
//存市的数组，依据省的数组加入
var shis=new Array();
shis[0]=new Array(new Option("--请选择市--",''));
shis[1]=new Array(new Option("长沙",'cs'),new Option("娄底",'ld'),new Option("永州",'yz'));
shis[2]=new Array(new Option("广州",'gz'),new Option("深圳",'sz'));
function change(obj){
var shi=document.getElementById('shi');
shi.options.length=0;
var index=sheng.selectedIndex;
for(var x in shis[index]){
shi.options[x]=shis[index][x]
}
}
</script>
</head>
<body onload="st()">
<div class='yemian' >
<div class="top">级联下拉列表</div>
<select class='s' id='sheng' onchange='change(this)'>
<option value=''>--请选择省--</option>
</select>
<select class='s' id='shi'>
<option value=''>--请选择市--</option>
</select>
</div>
</body>
</html>
