Is it possible to invite attendees to a public calendar using OWA?

Hello,

We use MS SBS 2003. I have a calendar setup in a public folder which works well except when the calendar is accessed through Outlook Web Access the invite attendies button is greyed out?

I require this feature so that users who are out of the office can arrange and modify meetings including inviting attendies and resources that I have setup.

Many thanks,

Chris.