var lastFaqClick=null;//上次点击的faq
window.onload=function(){
  var faq=document.getElementById("faq");
  var dls=faq.getElementsByTagName("dl");
  for (var i=0,dl;dl=dls[i];i++){
    var dt=dl.getElementsByTagName("dt")[0];//取得标题
     dt.id = "faq_dt_"+(Math.random()*100);
     dt.onclick=function(){
       var p=this.parentNode;//取得父节点
        if (lastFaqClick!=null&&lastFaqClick.id!=this.id){
          var dds=lastFaqClick.parentNode.getElementsByTagName("dd");
          for (var i=0,dd;dd=dds[i];i++)
            dd.style.display='none';
        }
        lastFaqClick=this;
        var dds=p.getElementsByTagName("dd");//取得该父节点所有的子节点，也就是所有的答案
        var tmpDisplay='none';
        if (gs(dds[0],'display')=='none')
          tmpDisplay='block';
        for (var i=0;i<dds.length;i++)
          dds[i].style.display=tmpDisplay;
      }
  }
}
/**
*取得元素的真实css属性
*written in 06.7 sheneyan
*/
function gs(d,a){
  if (d.currentStyle){
    var curVal=d.currentStyle[a]
  }else{
    var curVal=document.defaultView.getComputedStyle(d, null)[a]
  }
  return curVal;
}// JavaScript Document