Need javascript to change thumbnail image with different views

I need a script written for a thumbnail view of a product. There is a front and back view of the product, as well as a zoom in and zoom out buttons. The color of the product can also be changed from a menu/list. The code has been written for the color change but what I need is for the menu to know what state the thumbnail is in. Whether or not its viewing the back of the product or the front so the color can change accordingly. Here is a link to what is done so far. [login to view URL] the zoom, and front and back buttons have no functionality yet, this is what I need to be integrated.