function position(nazev,img,top,left)
{	
  self.document[nazev].src=img;
  
  var obj = document.getElementById(nazev);
  obj.style.display = 'block';
  obj.style.position = 'absolute';
  obj.style.left = left;
  obj.style.top = top;
}	


function hideimg(nazev)
{
  self.document[nazev].src='';
  document.getElementById(nazev).style.display = 'none';
}