Kirupa photogallery: image fade out after preloading

first of all, the kirupa photogallery tutorial is something i learned a lot from and 'ive modified for all kind of needs.

but now i would like to have it changed. when you klick on next or previous image, the image fades out, the new image is being loaded and when it has been loaded this new image fades in.

i would like the change order of these 3 actions (fade out, loading, fade in).
is it possible to have the old image not faded out while loading, and that it only fades out when the nex image has been loaded. this fade out would be followed by a fade in of the new image.

some one who got an idea how to realize this?