function resize()
{
  l=document.getElementById('left');
  c=document.getElementById('main');
  r=document.getElementById('right');

  var max=0;
  if(l.clientHeight>max) max=l.clientHeight;
  if(c.clientHeight>max) max=c.clientHeight;
  if(r.clientHeight>max) max=r.clientHeight;

  l.style.height=(max)+"px";
  c.style.height=(max)+"px";
  r.style.height=(max)+"px";

}