Not having a URL to look at, it makes it a bit tough to assist. Here's a solution I helped another user who was trying to (I think) do the same thing.

In that user's case, I was able to use Firebug to examine his site and determined that the ID associated with the menu item was 910. You can use Firebug (A Firefox addin) to determine the specific characteristics of your menu tab and then adjust the above code accordingly.