var do_show = 0;

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

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

  var MainTitles = document.getElementById('CCTable').rows[0].cells;
  MainTitles[0].rowSpan=YearSpan;
  MainTitles[1].colSpan=MainSpan;
  MainTitles[2].colSpan=MainSpan;

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

  var SubTitles=SubRows[1].getElementsByTagName('th');
  SubTitles[0].style.display=stl;
  SubTitles[1].style.display=stl;
  SubTitles[2].style.display=stl;
  SubTitles[3].style.display=stl;

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

} //function show_hide_column