Set alerts in calendar when viewing ical server via browser

Does anybody have any ideas if it is possible to set alerts when viewing ical server via a browser?

Scenario:

Manager is using a Mac and iCal server, Secretary is using a p.c. (Win XP) and viewing/editing Managers iCal by browsing into iCal server with Firefox.

Manager can make and edit entries and set reminders/alerts, Secretary can only make and edit entries -not set reminders or alerts from the web interface.

There doesn't appear to be any options for setting alerts via web interface.

Any suggestions would be appreciated.

Thanks in advance.

P.S. iCal Server running 10.6.8