I have a HTC Tilt with AT&T and it is synced with my 2007 Outlook calendar. I have appt set in my calendar and use it everyday. I hit dismiss whenever a reminder for an appt comes up but if i try to view my appts from last week they are deleted. I think hitting dismiss does this. Should i hit ignore?

My goal is to NOT delete them from my calendar so i can look back at my past appts. HOW DO I DO THIS? I have check the settings and all sorts of stuff and have not found a setting for this.