Screen programming (VMA412)

Hi sweet people,
First, I want to warn you that i'm a french student so I apologize for my english.

Then let me explain you my problem:
At school we have a big project and my biggest part is adding a screen to a vibrating bench.

Well I have choosen the VMA412 screen (VMA412: Velleman : 2.8" 320x240 Touchscreen Display for Arduino Boards : Electronic Kits & Projects) I have many programs exemples but I can't make mine working.

I want to display images, and I want to create some ""invisibles"" buttons on it then when clicking on one of this button, I want to display an other screen with other invisibles buttons.

The problem is that the exemple for displaying BMPpictures isn't working, and I don't really know how to make my buttons "invisibles".

Thanks for your help, ... save me.