function set_height()
{
  var Layer=document.getElementById('content');
  var Layer1=document.getElementById('content1');
  var Layer2=document.getElementById('content2');
  var Layer3=document.getElementById('content3');
  var h=Layer.offsetHeight;
  elementheight=h%29;
  //alert(elementheight);
  var neheight=h+(29-elementheight);
  //alert(neheight);
  //neheight+=10;
  Layer.style.height=neheight+'px';
  Layer1.style.height=neheight+'px';
  Layer2.style.height=neheight+'px';
  Layer3.style.height=neheight+'px';
  //alert("test");   	
}