关于 document.getElementById 多个ID

Question

现在 ID为 navigation 已经实现下拉菜单功能，想为同一页面上 ID 为 navigation2 也实现同样功能。
请问怎么修改下面代码增加  navigation2 。<script type="text/javascript">
function init_navigation(){
        var obj=document.getElementById("navigation");
        var liObj=obj.getElementsByTagName("li");
        var okLiObj=new Array();
        var length=liObj.length;
        var currentObj=null;
        for(var i=0;i<length;i++){
                currentObj=liObj[i];
                if(currentObj.parentNode==obj){
                        okLiObj.push(currentObj);
                }
        }
        length=okLiObj.length;
        for(var i=0;i<length;i++){
                okLiObj[i].onmouseover=function(){
                        this.className+=" show";
                }
                okLiObj[i].onmouseout=function(){
                        this.className=this.className.replace("show","");
                }
                okLiObj[i].onclick=function(){
                        this.className=this.className.replace("show","");
                }
        }
}
init_navigation();
</script>

Answer 1

function init_navigation(id){
    var obj = document.getElementById(id);
    ...
}

Answer 2

写成一个方法把 。
分别传入 navigation ， navigation2 。