function setVisible(obj, adr)
{   
   var cObj = obj;
	obj = document.getElementById(obj);
	if (obj.style.left == 0) placeIt(cObj);
	var ifr = document.getElementById('ifsadrzaj');
	ifr.src = (obj.style.visibility == 'visible') ? 'Prazna.htm' : adr; 
	obj.style.visibility = (obj.style.visibility == 'visible') ? 'hidden' : 'visible';
}

function placeIt(obj)
{
	obj = document.getElementById(obj);
   var nPoz = new Array();
   nPoz = getScrollXY();
   theLeft = nPoz[0];
   theTop = nPoz[1];
   theLeft += (screen.availWidth/2)-200;
   theTop += (screen.availHeight/2)-250;
   
	obj.style.left = theLeft + 'px' ;
	obj.style.top = theTop + 'px' ;
	//setTimeout("placeIt('layer1')",500);
}

function getScrollXY() {
  var scrOfX = 0, scrOfY = 0;
  if( typeof( window.pageYOffset ) == 'number' )
  {
    //Netscape compliant
    scrOfY = window.pageYOffset;
    scrOfX = window.pageXOffset;
  } 
  else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) 
  {
    //DOM compliant
    scrOfY = document.body.scrollTop;
    scrOfX = document.body.scrollLeft;
  } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
    //IE6 standards compliant mode
    scrOfY = document.documentElement.scrollTop;
    scrOfX = document.documentElement.scrollLeft;
  }  
  return [ scrOfX, scrOfY ];
}

window.onscroll = function(){setTimeout("placeIt('popArt')",250);};