function toggle_dl_display () {
  var dts = document.getElementsByTagName('dt');
  for (i=0;i<dts.length;i++) {
    dts[i].nextSibling.style.display = 'none';
    addEvent(dts[i],'mouseover',function(){this.style.background='#ccc';this.style.cursor='pointer';});
    addEvent(dts[i],'mouseout',function(){this.style.background='#fff';this.style.cursor='pointer';});
    addEvent(dts[i],'click',function(){if(this.nextSibling.style.display=='none'){this.nextSibling.style.display='block';}else{this.nextSibling.style.display='none';}});
  }
}
addEvent(window,'load',toggle_dl_display);