var activeLayer = "aug13"
function jumper(showLayer,l,t)
{
  if(document.all)
  {
     eval('document.all.'+activeLayer+'.style.visibility="hidden"');      eval('document.all.'+showLayer+'.style.visibility="visible"');
  }
  else if(document.getElementById)
  {
     document.getElementById(activeLayer).style.visibility="hidden";
     document.getElementById(showLayer).style.visibility="visible";
  }
  else
  {
     eval('document.'+activeLayer+'.visibility="hide"');
     eval('document.'+showLayer+'.visibility="show"');
  }

  activeLayer = showLayer;
}