var imagesPath = "../img/";
var imagesExt = "gif";


function NewImage(arg)
{
  if (document.images)
  {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  };
};


var preloadFlag = false;
function ChangeImages()
{
  if (document.images && (preloadFlag == true))
  {
    for (var i=0; i<ChangeImages.arguments.length; i+=2)
    {
      document[ChangeImages.arguments[i]].src = ChangeImages.arguments[i+1];
    };
  };
};


function over(name, state)
{
  if(0 == state) // out
  {
    postfix = "."+imagesExt;
  }
  else if(1 == state) // in
  {
    postfix = "-o."+imagesExt;
  }
  else if(2 == state) // down
  {
    postfix = "-d."+imagesExt;
  }
  else
  {
    alert("Unknown rollover state");
    return;
  };

  ChangeImages(name, imagesPath + name + postfix);
};


function PreloadImages()
{
  if (document.images)
  {
    var preloaded_images = new Array;
    var image_src = "";
    for (var i=0; i<PreloadImages.arguments.length; i++)
    {
      image_src = imagesPath + PreloadImages.arguments[i] + "." + imagesExt;
      preloaded_images[i] = NewImage(image_src);
    };

    preloadFlag = true;
  }
}