Alarm, 2003 Stratus SXT

Hey all, I have a 2003 SXT with an alarm system. I am not sure how to tell if it is a factory system, since the FOB does not say Dodge (or other Dodge indication).

The problem just started this morning, at 5:30. The alarm went off without any apparent reason. After silencing it by clicking the Lock button, it went off about 10 minutes later. This continued, with the time intervals shortening a little.

Finally, I used the Internet to tell me to use the key to lock/unlock the door. After further investigation, we discovered that the alarm will go off only if we use the Lock button on the key FOB.

So, what do I do? The manual does not diagram anything for an alarm/anti-theft system. I am having trouble finding results on the internet as well.

Thanks,
Mike