sharepoint tabs

Hey,

We have a WSS 3.0 site running on a windows 2003 server.

I have set this site up myself and am just looking for a bit of help.

I have tabs along the top such as: Home, HR, IT etc.
I have a management tab too which i want to Hide if possible?
i will be putting some reports onto this that i only want certain people to view.

for example:

if a manager logs on, the tab will be visible in the top navigation bar.

if an average user logs on, there will be no tab.

i want this so the other staff dont feel like they are missing out on anything or that we are trying to hide something.

i have google'd this issue but cant seem to find anything useful..

any help would be great..

thanks