Customs vs. Recalcitrant Passenger

[kevin]

Folks,

Next week I am going back to Canada to drop off a couple of friends. I told both of them weeks ago to get passports, or certified copies of their birth certificates, to use for the crossing. One of them forgot to do so, and now is whining that he crosses the border back and forth all the time in a car with just his drivers license. Has anyone out there crossed in either direction in a airplane with just a DL? Any comments or suggestions?

Thanks,

Kevin