关于JS的一个二级关联下拉菜单的问题，请各位帮忙

[brucecj1227]

我想做一个二级关联下拉菜单，一级的值为:
运动
音乐
游戏
影视
模型
动漫
阅读
热点话题宠物

二级的值为:
球类运动","非球类运动","其他
流行乐","非流行乐","其他"
网络游戏","单机游戏","其他"
"电影","电视剧","其他"
"动漫模型","电影模型","其他"
"动画","漫画","其他")
"书籍","报纸","杂志","其他"
"恶搞类","时尚类","其他"
"有生命宠物","其他"

一级的一行对应二级的一行，有哪位大哥能给点源代码的，小弟感激不尽
哦，对了，是JSP的