How do I create a iventory system with quick slots

I need to create a inventory system, with quick slot function like mmorpg,

something like this

http://gamingandtechnetwork.files.wordpress.com/2013/06/untitled2.png

Thre are some example on this forum, just search for inventory..

It's quite complicated to make, both the graphic side and the animation side, but it is do-able..

I guess using arrays to store the data would be the beginning..