How to cap a shared folder

Hi,
I have been asked to set a maximum folder size on a shared network drive. The folder is on a partition on a Windows Server 2003 SBS server. Inside the shared folder, each user has their own folder. Is it possible to set a maximum size for each of these folders? Is it possible to set different maximums, i.e. Director has 1GB, standard user has 0.5GB?

Thanks,
Chuck