Javascript:

程序代码
/*
函数名称: Scroll
Scroll(obj, h, s)
参数说明:
obj,[object] id值或对象. 必需
h,[height] 展开后的高度. 可选(默认为200px)
s,[speed] 展开速度,值越小展开速度越慢. 可选(默认为1.2){建议取值为1.1到2.0之间[例如:1.17]}.
函数返回值:
true 展开(对象的高度等于展开后的高度)
false 关闭(对象的高度等于原始高度)
*/
function Scroll(obj, h, s){
var h = h || 200;
var s = s || 1.2;
var obj = typeof(obj)=="string"?document.getElementById(obj):obj;
if(obj == undefined){return false;}
var status = obj.getAttribute("status")==null;
var oh = parseInt(obj.offsetHeight);
obj.style.height = oh;
obj.style.display = "block";
obj.style.overflow = "hidden";
if(obj.getAttribute("oldHeight") == null){
obj.setAttribute("oldHeight", oh);
}else{
var oldH = Math.ceil(obj.getAttribute("oldHeight"));
}
var reSet = function(){
if(status){
if(oh < h){
oh = Math.ceil(h-(h-oh)/s);
obj.style.height = oh+"px";
}else{
obj.setAttribute("status",false);
window.clearInterval(IntervalId);
}
}else{
obj.style.height = oldH+"px";
obj.removeAttribute("status");
window.clearInterval(IntervalId);
}
}
var IntervalId = window.setInterval(reSet,10);
return status;
}
window.onload= function(){
var $ = function(id){return document.getElementById(id)};

$('btn').onclick = function(){
Scroll('test',this.scrollHeight,1.2);
}

$('menu').onclick = function(){
Scroll('menu',this.scrollHeight,1.2);
}
}

Html代码:

程序代码
<dl>
<dt id="btn" style="cursor:pointer; background-color:#009999; width:200px;">展开收缩</dt>
<dd id="test" style="background-color:#33CCCC; overflow:hidden; width:200px; height:0;">
内容
</dd>
</dl>

程序代码
<div id="menu" style="border:1px solid #ccc;width:160px;height:16px;text-align:center;cursor:pointer;overflow:hidden;">
内容内容内容内容内容
</div>