YOU NEED to get from London to Rome tomorrow morning - then catch a flight from Rome to Frankfurt later that afternoon, before flying on to Madrid. How do you plan the trip? How do you find out the cheapest fares? Who can tell you about seat availability?

A travel agent is the obvious place to start. But what if you need the information after office hours? Or what if you cannot cope with all the to'ing and fro'ing?

Would it not be more sensible if you could just plug into the same computer system that the travel agency accesses? Well, you can. Official Airline Guides (OAG) has an Electronic Edition Travel Service available to anybody with a PC and a modem. For pounds 20 an hour peak (plus the ordinary telephone charge) - pounds 14 an hour off-peak - you can put together your own itinerary.

The system does not allow you to make the booking: you have to pass the itinerary to a travel agent for ticketing - but all the hard work will have been done.

ABC World Airways Guide, published monthly, is now available as a CD-ROM disk accessible to anyone with a CD-ROM linked to an IBM PC and costs pounds 387.75 for an annual subscription. The ABC Travel Disc, which also costs pounds 387.75 for an annual subscription with monthly updates, provides information on 450,000 flights. There is also data on transport , vaccination and visa requirements, public holidays, banking and business hours as well as advice on local etiquette.

To plan an itinerary, the user keys in the departure and destination airports, date of travel, preferred timings and airlines and, using this information, the ABC Travel Disc will display the information, highlighting the most suitable flights.

While the CD-ROM reader can handle information more quickly than an ordinary PC floppy disk system, OAG has decided that making its guides available on floppy disks still makes the best sense. Mike Mullany, director of electronic sales for OAG, says compared with the relatively few CD-ROM readers in offices, there are more than 50m IBM-PC compatible computers in the business market.

OAG produces two guides on floppy disk: European and the North American editions - costing pounds 166 each for a year's subscription. OAG is looking at producing a worldwide edition of its guide, which would cost around pounds 350.

You should be warned, however: playing with flight schedules using the disks becomes addictive. My son has had more fun putting together complex itineraries around Europe and America than he ever had from Lemmings]

Further information: Customer Services, Reed Travel Group, ABC International Division, Church Street, Dunstable, Bedfordshire LU5 4HB (0582 695050); Official Airline Guides, Bridge House, 4 Lyons Crescent, Tonbridge, Kent TN9 1EX (0732 770644).