http://www.bitlink.co.jp/js/accordion2.js

1var accordion=function(){
2	var tm=sp=4;
3	function slider(n){this.nm=n; this.arr=[]}
4	slider.prototype.init=function(t,c,k){
5		var a,h,s,l,i; a=document.getElementById(t); this.sl=k?k:'';
6		h=a.getElementsByTagName('dt'); s=a.getElementsByTagName('dd'); this.l=h.length;
7		for(i=0;i<this.l;i++){var d=h[i]; this.arr[i]=d; d.onclick=new Function(this.nm+'.pro(this)'); if(c==i){d.className=this.sl}}
8		l=s.length;
9		for(i=0;i<l;i++){var d=s[i]; d.mh=d.offsetHeight; if(c!=i){d.style.height=0; d.style.display='none'}}
10	}
11	slider.prototype.pro=function(d){
12		for(var i=0;i<this.l;i++){
13			var h=this.arr[i], s=h.nextSibling; s=s.nodeType!=1?s.nextSibling:s; clearInterval(s.tm);
14			if(h==d&&s.style.display=='none'){s.style.display=''; su(s,1); h.className=this.sl}
15			else if(s.style.display==''){su(s,-1); h.className=''}
16		}
17	}
18	function su(c,f){c.tm=setInterval(function(){sl(c,f)},tm)}
19	function sl(c,f){
20		var h=c.offsetHeight, m=c.mh, d=f==1?m-h:h; c.style.height=h+(Math.ceil(d/sp)*f)+'px';
21		c.style.opacity=h/m; c.style.filter='alpha(opacity='+h*100/m+')';
22		if(f==1&&h>=m){clearInterval(c.tm)}else if(f!=1&&h==1){c.style.display='none'; clearInterval(c.tm)}
23	}
24	return{slider:slider}
25}();