I made a huge mistake (actually two) when I bought an airline ticket online: What do I do?

Mistakes, I’ve made a few, but then again, too few to mention. Well, these bear mentioning in case they ever happen to you while you are booking an airline ticket online.

Stupid mistake No. 1: At the end of a long day recently, I went online and bought two round-trip tickets from Los Angeles to Seattle at a price I liked and had the itineraries e-mailed to myself and my husband.

The next day my husband checked the flights and called to tell me I was celebrating Backwards Day early: I had inadvertently booked the flights starting in Seattle instead of Los Angeles. (Clearly this wouldn’t have happened if I had made my reservation by phone or through a travel agent.) My head was spinning as I quickly realized the change fees would cost as much as each leg of the journey.

Fortunately, my panic was unfounded. A call to the airline, Virgin America, and an explanation of the problem quickly put things right. A reservation agent rebooked the flights in the proper direction, sent a revised e-mail itinerary and charged me nothing.

Is this business as usual? It depends on the airline:

-- American Airlines, spokesman Tim Smith said in an e-mail, likely would correct the mistake and waive change fees if you call within 24 hours. He added that any difference in fare may apply.

-- As noted above, Virgin America also will fix the error gratis as long you call within 24 hours, a reservation agent confirmed.

-- JetBlue Airways, on the other hand, doesn’t suffer fools. “Once a reservation is confirmed, change policies are in effect at the time the call or online purchase is complete,” spokeswoman Alison Croyle said in an e-mail.

The scenario gets more complicated if you book through a third-party online reservation system:

-- Orbitz, for example, generally offers a “courtesy cancel” until 10 p.m. CST the following day. But it too is bound by individual airline policies. Orbitz spokesman Brian Hoyt tells me that most airlines offer a 24-hour cancellation, but some give you only four hours to discover a blunder.

-- Travelocity says it will cancel the errant ticket within 24 hours without penalty; after that, change fees apply, spokeswoman Meredith McKee said in an e-mail. (Travelocity and Orbitz say to call them to fix the error; don’t try to muddle through online.)

Stupid mistake No. 2: In a different online ticket purchase, I inadvertently filled in the wrong date of birth for a friend who would be flying with me to San Francisco.

The airline again was Virgin America. I called a reservation agent to learn that the mistake is not fixable online, but that the airline will make the change by phone without charge. Why bother? The Transportation Security Administration says a wrong date of birth on an airline ticket could cause a delay and trigger extra screening for some passengers.

Why so many mistakes? I have no defense except to note that in both cases I was making the reservations late at night.

Now that all of this has been straightened out, I’ll have to think of something else to do on Backwards Day, Jan. 31.