pocket pc and appointment clashes

help.
Please could you tell me if there is any way of setting
an alert on outlook 2000 to tell me that 2 appointments
have been booked in on my calendar for the same time? The
problem is that I use an ipaq to set up appointments when
I'm out of the office, but I also have my calendar shared
so people can also book appointments for me. When I
synchronize my ipaq with my pc the appointments appear
side by side. The only way of resolving this at the
moment is to go though my calendar and check each
appointment. The problem being that my appointments are
booked weeks in advance.