function do_hhover() { if (this.className.charAt(0) != '-') this.className='- '+this.className+' hovered';}
function un_hhover() { if (this.className.charAt(0) == '-') this.className=this.className.substring(2,this.className.length-8); }

function initHelpHover() {
  var helps = getElementsByClassName('help');
  for (var i=0;i<helps.length;i++) {
    helps[i].onmouseover = do_hhover;
    helps[i].onmouseout = un_hhover;
  }
}

addLoadEvent(initHelpHover);