Thanks,
Thanks man.
I already tried locked property but one drawback with locked property is it lock the appointment event to move. I mean we can't drag the appointment.
Any other solution???
You should use the BeforeAppointmentEdited event (2009 v2 has it). This event only fires when the text (subject of the appointment) is being edited in the day view. you then simply cancel the event to essentially make it non-editable.