ajkiddo

Last night the alarm (the horn) randomly started going off my 2006 ML500. It doesn't matter if the doors are is locked or unlocked, doors open or closed, parked on flat, or on a hill or a side slant. The alarm sometimes just honks twice, other times is goes off for a couple of minutes. The key fob doesn't work while it is going off and only putting the key in the ignitions stops it or just have to wait for it to stop. I have turned off the tow alarm off, tried to reset everything I could find to reset (which wasn't much).
After a visit to the dealers service department this morning, in which they were no help and just told me to not use the fob and come back late next week (yup, not happy with them right now, since I was there at my appt time and he was just down right rude). Luckily I have 3 other dealers within an hour of me, now have to wait until tomorrow morning to go a different dealer on the other side of town to hopefully get it fixed. But until then I am concerned that if this keeps up I will have a dead battery by morning, if I can't figure out how to stop this, at least temporally.
Any suggestions? Has anyone else had this happen to their ML500.
Thanxs for the sleep deprived in my neighbor and myself