Volkswagen jetta help?

I left the sunroof in my car open 3 days ago and we got a little rain. The inside of my car got wet and I cleaned it as much as I could. In the morning after my car has been off all night the windows are fogged up and moist inside. I figured that would go away in time. Well yesterday I tried to start my car, which aside from needing new plugs and wires has run fine until now, but it wouldn't start and the battery light was on. After jumping it it seemed to run normally again for about an hour. Then I noticed that the airbag light had come on and there was a loud constant beeping, almost like an alarm, going off on the inside of my car. I've driven it a few times with the beeping noise and aside from that its not running any differently. I'm wondering if the water could have done something, or maybe it's a coincidence and something else happened around the same time. If anyone has any idea what this could be, or what I could do to correct the problem I would greatly appreciate it!