要求:
2个下来框,选择1级菜单后,2级菜单出现相应的备选项。如果没有选择则不能提交。
先创建html文件
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<form>
<select id="province">
<option selected="selected">请选择...</option>
</select>
<select id="city">
<option selected="selected">请选择...</option>
</select>
<button type="submit" id="where_submit" disabled="disabled">提交</button>
</form>
</body>
<script type="text/javascript">
var provinces=['辽宁','北京','上海','吉林','浙江'];
//最新添加的省份放在最前面
var choice=['请选择...']
var zhejiang=['杭州','嘉兴','宁波','绍兴'];
var shanghai=['金山','闸北','普陀','徐汇'];
var jilin=['长春','辽源','吉林','四平'];
var beijing=['海淀','朝阳','东城','西城'];
var liaoning=['沈阳','大连','盘锦','锦州','辽阳','鞍山']
//城市排序由后到前
var citys=new Array;
citys[0]=choice;
citys[1]=zhejiang;
citys[2]=jilin;