var currentThumbId = false;
var previewImage = false;

function showPreview(newSrc, thumbId)
{
	if (previewImage) previewImage.src = newSrc;
	revealThumbnail(currentThumbId);
	currentThumbId = thumbId;
}
	
function revealThumbnail(thumbId)
{
	var thumb = document.getElementById(thumbId);
	thumb.style.filter = 'alpha(opacity=100)';
	thumb.style.opacity = 1;
}

function dimThumbnail(thumbId)
{
	var thumb = document.getElementById(thumbId);
	thumb.style.filter = 'alpha(opacity=50)';
	thumb.style.opacity = 0.5;
}

function mouseOverThumb(thumbId) {
	if (thumbId == currentThumbId) {
		revealThumbnail(thumbId);
	} else {
		dimThumbnail(thumbId);
	}
}

function mouseOutThumb(thumbId) {
	if (thumbId == currentThumbId) {
		dimThumbnail(thumbId);
	} else {
		revealThumbnail(thumbId);
	}
}

function initGalleryScript(defaultThumbId)
{
	// Initialize the preview image.
	var previewImagePane = document.getElementById('previewPane');
	var images = previewImagePane.getElementsByTagName('IMG');
	if (images.length > 0) {
		previewImage = images[0];
	}
	
	// Dim the default thumbnail.
	dimThumbnail(defaultThumbId);
	currentThumbId = defaultThumbId;
}