Fix CSS issue with z-index and linking

See this page: [login to view URL] If you hover your mouse over the top part of the site a blue menu will drop down with links to other pages. Right now the links are not clickable because the z-index of the .centered div is laying on top of it. I need this fixed so that the links can be clicked on. Also the blue drop down menu must function and look the same as it does now. The fix must be cross browser compatible. Let me know if there are any questions about the project.