Javascript Z-Index manipulation…

I have 9 overlapping layers. I want to make whatever layer is clicked on come to the front and all other layers go back to their respective positions. This is for a navigation bar. To be more specific:

I have 9 tabs. Each one representing a different page. When I click on tab2, it should appear in front of tab 1. However, since someone might click on tab9 and then tab2, I need tab9 to go all the way back to its original position whenever another tab is selected. I was planning on doing this in javascript, however, I am open to any langugage that will get the job done. Any suggestions as to how I might accomplish this would be welcome.