Adding Cross-Fade to Thumbnail Viewer II

[syswriter]

1) Script Title: Image Thumbnail Viewer II

2) Script URL (on DD): http://www.dynamicdrive.com/dynamici...thumbnail2.htm

3) Describe problem: I would like to add a cross-fade to the Thumbnail Viewer II.
This viewer has text descriptions that appear below the slideshow picture rather than on top, giving it a cleaner appearance which I prefer.
What is the best way to add a cross-fade?