@acrylian: "Always the same for all "scuba" subalbums as a "section" then use the uralbum function I linked."
Thats exactly what I want i.e.
if (url contains scuba-diving)
{show scuba.jpg as the top header image for parent album and all downpath subalbums right till the image is displayed}
else {header.jpg}
but I dont know how to use the function you linked. I understand the concept of function but since just started php cant write the codes yet. Anyway I understand you cant write codes here for all visitors so its ok. I really appreciate the help I've got in the last few days.
@fretzl: really appreciate your effort, thanks a lot. May you always be in a good mood

Regarding the codeblock, it works fine for all the albums and sub-albums however the image code does not work. When you click on the thumbnail to open the image then only a black screen is displayed.
Can you please include the option in the code that if there is nothing in the codeblock then the default header.jpg is displayed, since a new user might not know about the code block.
I am really sorry I am asking too much from you guys but hopefully this is my last design issue.
Regards