Licensing ? - How to reserve 'Solidworks Professional' licenses.

Recently upgraded our company to 2010 and am pretty new to Solidworks.  Anyway, I recently had a user complain that they were unable to use their Professional license because someone in another branch (who doesn't need access to it, only standard) had grabbed it.  Is there any way to specify who would receive a professional license vs. who would not?  Is it something that needs to be done during installation, or can it be changed afterward? 

Thanks!

SolidworksAdministration