I am the manager of a small coffee shop that has this espresso machine and I do not have the manual that came when it was originally purchased. There are three buttons on the far right side where the steamer is, that has a green lighted area when turned on. I do not know what these are or what they are used for. The top one has a figure next to it that looks like an upside down coffee cup. The middle one, underneath that first one, has a zigzag figure with an arrow on one end pointing up. And the third one, on the bottom for the middle one has a circle with a verticle line in the middle of it. Please help. I barely know how to clean this machine. Thanks!