function toggleDiv(divid)
{
  var elem, vis;
  if (document.getElementById) elem = document.getElementById(divid);
  else if (document.all) elem = document.all[divid];
  else if (document.layers) elem = document.layers[divid];
  vis = elem.style;
  if (vis.display == '' && elem.offsetWidth != undefined && 
      elem.offsetHeight != undefined)
    vis.display = (elem.offsetWidth != 0 && elem.offsetHeight != 0)
                   ? 'block' : 'none';
  vis.display = (vis.display=='' || vis.display == 'block') ? 'none':'block';
}