var do_show = 0;

function show_hide_column()
{
  var stl;
  var YearSpan;
  var AgeSpan;
  var MainSpan;

  if (do_show)
  {
    stl = '';
    YearSpan = "3";
    AgeSpan = "8";
    MainSpan = "2";
    document.getElementById("HideSE").innerHTML="Hide Standard Error";
    do_show = 0;  //false
  }
  else
    {
      stl = 'none';
      YearSpan = "3";
      AgeSpan = "4";
      MainSpan = "1";
      document.getElementById("HideSE").innerHTML="Show Standard Error";
      do_show = 1; //true
    } //else

  var MainTitles = document.getElementById('PATable').rows[0].cells;
  MainTitles[0].rowSpan=YearSpan;
  MainTitles[1].colSpan=AgeSpan;

  var SubTitles = document.getElementById('PATable').rows[1].cells;
  SubTitles[0].colSpan = MainSpan;
  SubTitles[1].colSpan = MainSpan;
  SubTitles[2].colSpan = MainSpan;
  SubTitles[3].colSpan = MainSpan;
  

  var Tbl=document.getElementById('PATable');
  var SubRows=Tbl.getElementsByTagName('tr');

  var RateSeTitles=SubRows[2].getElementsByTagName('th');
  RateSeTitles[0].style.display=stl;
  RateSeTitles[1].style.display=stl;
  RateSeTitles[2].style.display=stl;
  RateSeTitles[3].style.display=stl;
  RateSeTitles[4].style.display=stl;
  RateSeTitles[5].style.display=stl;
  RateSeTitles[6].style.display=stl;
  RateSeTitles[7].style.display=stl;
  

  for (var row=3;row<SubRows.length;row++)
  {
    var cels=SubRows[row].getElementsByTagName('td');
    cels[2].style.display=stl;
    cels[4].style.display=stl;
    cels[6].style.display=stl;
    cels[8].style.display=stl;
    

  }

} //function show_hide_column