Another attempt - menu system

1

so i really need help with this and just need some guidance on what methods to use to accomplish the menu found on this site:

http://www.dhondt-deuren-trappen.be/

My layout:

  1. Screen: 500 x 250
  2. 5 pictures each 100 wide
  3. on mouse over a picture, that picture becomes 300 wide and the rest of the pictures become 50 wide and move to the side (now when i say that they become 50 wide, it means that they get covered up and NOT resized)

any guidance? should i be looking into swapdepth, what kind of masking, etc.?
thx.