JSON+HTML实现国家省市联动选择效果

代码如下:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>json</title>
<script type="text/javascript">
<!--
var list=[{"name":"中国",
"value":"86",
"province":[{"name":"湖北",
"value":"430000",
"city":[{"name":"武汉","value":"wh"},
{"name":"黄冈","value":"hg"},
{"name":"襄阳","value":"xy"}]},
{"name":"河北",
"value":"100000",
"city":[{"name":"邯郸","value":"hd"},
{"name":"保定","value":"bd"},
{"name":"石家庄","value":"sjz"}]},

{"name":"湖南",
"value":"440000",
"city":[{"name":"长沙","value":"cs"},
{"name":"株洲","value":"zz"},
{"name":"衡阳","value":"hy"}]}]},
{"name":"美国",
"value":"22",
"province":[{"name":"阿肯色",
"value":"990000",
"city":[{"name":"纽约","value":"ny"},
{"name":"华盛顿","value":"hsd"},
{"name":"波士顿","value":"bsd"}]},

{"name":"阿哈哈",
"value":"980000",
"city":[{"name":"AA","value":"ahd"},
{"name":"BB","value":"abd"},
{"name":"CC","value":"asjz"}]}]

}];

function init(){
var _country=document.getElementById("country");
for(var e in list){
var opt_1=new Option(list[e].name,list[e].value);
_country.add(opt_1);
}
}

function toProvince(){
var _country=document.getElementById("country");
var _province=document.getElementById("province");
var _city=document.getElementById("city");
var v_country=_country.value;

_province.options.length=1;
_city.options.length=1;

for(var e in list){
if(list[e].value==v_country){
for( var p in list[e].province){
var opt_2=new Option(list[e].province[p].name,list[e].province[p].value);
_province.add(opt_2);

}
break;
}
}
}

function toCity(){
var _country=document.getElementById("country");
var _province=document.getElementById("province");
var _city=document.getElementById("city");

var v_country=_country.value;
var v_province=_province.value;

//_province.options.length=1;
_city.options.length=1;

for(var e in list){
if(list[e].value==v_country){
for( var p in list[e].province){
//alert(list[e].province[p].value);
if(list[e].province[p].value==v_province){
// alert(list[e].province[p].value);
for(var cc in list[e].province[p].city){
var opt_3=new Option(list[e].province[p].city[cc].name,list[e].province[p].city[cc].value);
_city.add(opt_3);
}

return;
}

}
break;
}
}
}

//-->
</script>
</head>

<body onload="init();";>
<select id="country" onchange="toProvince();">
<option value="-1">--请选择国家---</option>
</select>
<select id="province" onchange="toCity();">
<option value="-1">--请选择省份---</option>
</select>
<select id="city">
<option value="-1">--请选择市区---</option>
</select>

</body>
</html>