How can I change the header image by clicking on a thumbnail?

Hello.

I have a question if anybody know if it´s possible to make the header image change by clicking a thumbnail in the bar1-section?

To make it clear what I mean: The visitor see the regular header image. Below it there´s the menu and below the menu is some thumbnails of other images. If I click one of thoose, that image become the header image.

If this is possible, do anyone know how to do it?

Thanks

/ Gustav Kullander