Should I use online travel site or the airline site with a lap infant?

I want my daughter (1 yr old) in my lap but on many of the travel sites there is not an option for a lap infant. Will we run into problems when we fly? How do I book for a lap infant? Should I use the airline's website instead? My husband and I and baby are flying to boston and the travel sites have some cheaper fares.Should I use online travel site or the airline site with a lap infant?Airlines require that if you are bringing a LAP baby that you CALL and tell them as the childs name must appear on the passenger list for safety reasons. I think you can book on line...just call them and ask and then call back after you book the flight and give them the details so they will expect you to be bringing a baby. See site below to read United's policy...then call your specific airline.Should I use online travel site or the airline site with a lap infant?It depends on the airline. Some companies will charge you extra to book on the phone or in person, so the easiest thing to do, if you would rather book online, is simply add "plus infant" to the end of your first name while booking. You can take care of the lap child paperwork when you get to the airport. Make sure to bring a copy of the birth certificate or shot records so you have proof of age.