var topmenu1_over = new Image();
  topmenu1_over.src = "img/varosiportal_hover.gif";
  var topmenu1_out = new Image();
  topmenu1_out.src = "img/varosiportal.gif";

  var topmenu2_over = new Image();
  topmenu2_over.src = "img/hagyomany_hover.gif";
  var topmenu2_out = new Image();
  topmenu2_out.src = "img/hagyomany.gif";

  var topmenu3_over = new Image();
  topmenu3_over.src = "img/termeszet_hover.gif";
  var topmenu3_out = new Image();
  topmenu3_out.src = "img/termeszet.gif";

  var topmenu4_over = new Image();
  topmenu4_over.src = "img/kozerdeku_hover.gif";
  var topmenu4_out = new Image();
  topmenu4_out.src = "img/kozerdeku.gif";

 function SetImage(image_doc, image_mem) {
  var obj = document.getElementById(image_doc);

  if (obj) {
    obj.src = eval(image_mem + ".src");
  }
}