function getClientHeight()
{
  var h=0;
  if(document.compatMode == 'CSS1Compat' && !window.opera && document.documentElement && document.documentElement.clientHeight)
    h=document.documentElement.clientHeight;
  else if(document.body && document.body.clientHeight)
    h=document.body.clientHeight;
  else if( window.innerWidth, window.innerHeight, document.width ) 
  {
    h=window.innerHeight;
    if(document.width>window.innerWidth) h-=16;
  }
  return h;
}