Image navigation - Help needed

Hi everyone, I would like to create a page like the one below. I am wondering how I can create a navigation menu with the numbers like the one shown on the bottom right side of the picture. When you press a number the relevant pictures shoes up.

Here is the website: http://rory-gardiner.com/


Thank you very much

It is just JavaScript. You can look at page source and find how they implemented it or simple you can use jquery and update img src