That is because it is adding the "active" class on both tabs on both pages. But at least the syntax and result are correct. That means #3 is done. Now we can analyze what is wrong with the php that determines when to add the active class which must be wrong.
I just took a look at the code. It looks like there should be code that sets the variable:
to the value of the tab that should be active. It also looks like the old menu used to loop on a recordset and this one is hard coded. The code needs to be adjusted now so that only the current tab has the "active" class added.