function addEvent(obj, evType, fn){
 if (obj.addEventListener){
   obj.addEventListener(evType, fn, false);
   return true;
 } else if (obj.attachEvent){
   var r = obj.attachEvent("on"+evType, fn);
   return r;
 } else {
   return false;
 }
}
addEvent(window,"load",function(){seltab('box', 'head', 10, 1)});

<!--
// bpref = tab body prefix, hpref = tab header prefix
function seltab(bpref, hpref, id_max, selected) {
  if (! document.getElementById) return;
  for (i = 0; i <= id_max; i++) {
    if (! document.getElementById(bpref + i)) continue;
    if (i == selected) {
      document.getElementById(bpref + i).style.visibility = "visible";
      document.getElementById(bpref + i).style.position = "";
      document.getElementById(hpref + i).className = "open";
    } else {
      document.getElementById(bpref + i).style.visibility = "hidden";
      document.getElementById(bpref + i).style.position = "absolute";
      document.getElementById(hpref + i).className = "close";
    }
  }
}
// -->