var _imageStorage = { };

function changeImage(sender, strImageName, strImageUrl, regItemExists)
{
    var imageUrl = String(strImageUrl);
    var imageUrlID = imageUrl.replace(/[^a-zA-Z0-9]/g, "_");
    var imageName = String(strImageName);
    
    if (imageUrl.search(regItemExists) != -1)
    {
        if (!_imageStorage[imageUrlID])
        {
            _imageStorage[imageUrlID] = new Image();
            _imageStorage[imageUrlID].src = imageUrl;
        }
        document.images[imageName].src = _imageStorage[imageUrlID].src;
        document.images[imageName].style.display = "block";
        
        var oldPos = sender.style.position;
        sender.style.position = "absolute";

        document.images[imageName].style.top = (sender.offsetTop + sender.offsetHeight) + "px";
        document.images[imageName].style.left = (sender.offsetLeft + sender.offsetWidth) + "px";
		
		sender.style.position = oldPos;
    }
}

function hideImage(strImageName)
{
	var imageName = String(strImageName);
	document.images[imageName].style.display = "none";
}