Van gone haywire

So I went to the post office today to mail a couple of packages. Just a simple little trip. I couldn't find our normal key with the little remote thingy, so I had the spare which is just a key. I have used it plenty of time before, but today, my van decided to go crazy. We mailed our packages, got into the van, and put the key into the ignition, and suddenly our van started honking wildly at me, I'm sure reporting that I am a horrible stealing person to all around me. And it wouldn't stop! I turned the van on, and the honking raised a pitch. I turned it off, locked and unlocked the doors, turned it on again. Everyone walked past us and stared--I may have just abandoned it and pretended it wasn't ours, if that didn't mean getting 3 kids out and taking them...where? So it let me put it into gear and I slowly drove out of the parking lot and into a less public place, and tried to decided if I dare drive the half a mile home like that on a busy road. Then suddenly it stopped. But there was a blinking light and I had a suspicion that if I opened the door or tried to start it, it would start all over again. Then I decided to get out of the van, lock it, and unlock it with the key. As I opened the door, it started honking again, and I locked myself out, unlocked it with the key, and walla! Twenty plus minutes of humiliation, but at least I didn't get arrested...Usually my embarrassing moments these days always are due to certain children.