function sd(id,visibility)  // setdisplay
{
 if(document.getElementById)
 {
  var obj = document.getElementById(id);
  if(obj)
  {
   obj.style.display = visibility?"block":"none";
  }
 }
}

function ha()   //hide aal
{
sd('hr6',0);sd('hr5',0);sd('hr4',0);sd('hr3',0);sd('hr2',0);sd('hr1',0);
}

/* ukaz obrazek */

function winH() {
   if (window.innerHeight)
      /* NN4 a kompatibilní prohlížeče */
      return window.innerHeight;
   else if
   (document.documentElement &&
   document.documentElement.clientHeight)
      /* MSIE6 v std. režimu - Opera a Mozilla
      již uspěly s window.innerHeight */
      return document.documentElement.clientHeight;
   else if
   (document.body && document.body.clientHeight)
      /* starší MSIE + MSIE6 v quirk režimu */
      return document.body.clientHeight;
   else
      return null;
}


function getScrollOffset()
{
	if(document.documentElement.scrollTop)
		return document.documentElement.scrollTop;
	if(window.pageYOffset)
		return window.pageYOffset;
	return document.body.scrollTop;
}