What do the buttons on my 2000 323i BMW key do?

Hi, i just purchased a 2000 bmw model 323i. It came with a "remote" key, i have no idea what the heck the buttons do, here is a picture of the key, i no that the first button opens the trunk, the second button locks/unlocks the door, and i have no clue what the third button does. But i heard that if you hold different buttons down that it can do a different task, do anyone know what buttons to hold or push how many times, to do different things?

here is a picture of my key

http://www.bmw-online.com/Img/Img/Loop-L...

What do the buttons on my 2000 323i BMW key do?antivirus protection

the top button with the arrow on it unlocks the doors. Also, if the alarm is off and making a racket, you can turn it off with this button

The middle BMW button locks the doors. Press it a second time and the motion detector inside the car is disabled. This is useful when you have the windows open and you don't want accidental alarms if a person sticks his hand inside the cabin, for example. Deactivating the motion detector also deactivates the "movement" sensor installed in the car that would usually start the alarm when the car is moved around excessively, for example when a tow truck tries to move your car.

The bottom button is the trunk-opener button. Also, if you hold the button for a couple of seconds, you will activate the alarm. (basically the huge red panic buttons on other remote car keys.)