使用js实现的关联表单

使用js实现的关联表单，应用的主要知识是关于js中表单的应用：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #div{
            width: 100px;
            height: 100px;
        }
        select{
            width: 100px;
            height: 50px;
        }

    </style>
</head>
<body>
<label>
    <select id="province" name="province" >
        <option>请选择省份</option>
        <option >山东</option>
        <option >福建</option>
        <option >广州</option>
    </select>
</label>
<select id="city">
    <option>请选择城市</option>
</select>
<script type="text/javascript">
    window.onload=function(){
        var province=document.getElementById("province");
        var city=document.getElementById("city");
        var citys=[
            ["泰安","济南","青岛"],
            ["厦门","泉州","莆田"],
            ["广东","东莞","新乡"]
        ];
        province.onchange=function(){
            var procity=citys[province.selectedIndex-1];
            city.options.length=1;
            for(var i=0;i<procity.length;i++){
                city.add(new Option(procity[i],procity[i]));
                city.children[0].setAttribute("selected","selected");
            }
        }
    }
</script>

</body>
</html>

　　如上：

知识点：html中表单选项的应用