function compareWindow(url,id) {
  var width = 700
  var height = 400
  
  var leftVal = (width - screen.width) / 2;
  var topVal = (height - screen.height) / 2;
  window.open(url,id,'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,copyhistory=no,width='+width+',height='+height+',left='+leftVal+',top='+topVal)
}

function update_on(obrazek) {
	document.getElementById( obrazek ).src='images/gfx/pprogress_on.gif';
}

function update_off(obrazek) {
	document.getElementById( obrazek ).src='images/gfx/pprogress_off.gif';
}