Returning records with null values

[aaearhart]

hello-

I have a report with data from four different tables. It's essentially a
Trip Itinerary report for a traveler to print out before they travel.

data for the report (can) come(s) from four tables:

T-Trips T-TripFlights T-TripHotels T-TripRentalCars

now, of course, there is always one trip and the T-Trips.TripID value is my
link through this all.

however, for each trip a traveler...
may have one or many flights
may have no flights
may have one or many hotels
may have no hotels
may have one or many rental cars
may have no rental cars

so far, my report is only returning the records where a traveler has
flights, hotels and cars, not instances where a travele has no flights and/or
no hotels and/or no cars. i'm certain this is because the sub(?) records have
nulls in them - assuming this is related to their primary key.

how can i get my report to display all info for trips even if there are nulls?

thanks!
/amelia