function  maximiser()
{
  var h = document.getElementById('row3').offsetHeight - 12;
  if(h<216) h=206;
  document.getElementById('row3column1').style.height = h + 'px';
  document.getElementById('row3column2').style.height = h + 'px';
  document.getElementById('row3column3').style.height = h + 'px';
  document.getElementById('row3column4').style.height = h + 'px';
  var h1 = document.getElementById('row2column1').offsetHeight;
  h = document.getElementById('row2column2').offsetHeight;
  if(h<h1) h=h1;
  document.getElementById('row2column1').style.height = h + 'px';
  document.getElementById('row2column2').style.height = h + 'px';
  h1 = document.getElementById('row2column3').offsetHeight;
  h = document.getElementById('row2column4').offsetHeight;
  if(h<h1) h=h1;
  document.getElementById('row2column3').style.height = h + 'px';
  document.getElementById('row2column4').style.height = h + 'px';
}