function setpagelength() {  
  econtent = document.getElementById('main');  
  esidebar = document.getElementById('sidebar'); 
  hc = econtent.clientHeight;  
  hs = esidebar.clientHeight;	
  nl = Math.max(hc,hs);	
  nl = nl + 20;	
  nl = Math.max(nl, 400);  
  econtent.style.height = nl+'px';  
  esidebar.style.height = nl+'px';
}