The Technically Challenged #3

I recently saw a distraught young lady weeping beside her car. "Do you need some help?" I asked.

She replied, "I knew I should have replaced the battery in this remote door unlocker. Now I can't get into my car. Do you think they (pointing to a distant convenience store) would have a battery for this?"

"Hmmm, I dunno. Do you have an alarm, too?" I asked.

"No, just this remote 'thingy,'" she answered, handing it and the car keys to me.

As I took the key and manually unlocked the door, I replied, "Why don't you drive over there and check about the batteries...it's a long walk."