function vertical_gallery
folder, say 'splashes_800'
max_width, ex: 640
border, 0 (none) or 1-20
RANDOM, 1:shuffle - 2:asc - 3:desc - 4:latest
max_pics, ex: 10
resized_width, 0
file_hint, usually '*' or, say, 'cam'
show_filename, 0, 1 or 2
BACK, usually 0 - 1:display a back arrow
PIC_DATA, 0:none - 1:yes