Processing Messages (the processMessage procedure):
- All messages sent to a macro are passed to the processMessage procedure.
  - A simple processMessage procedure looks like this:
```
procedure processMessage m:msg
  say "Got message name=^{msg.name} with &
       info=^{msg.info}, data=^{msg.data} &
       from ^{msg.from}"
return
```
  - Most processMessage procedures include a large IF...ELSEIF...ELSE...ENDIF block used to process the messages based on their name, data and/or source (i.e. from).

X-Midas Users Take Note:
The `processMessage` procedure in NeXtMidas takes the place of the `controls` section of X-Midas. All graphical widgets in NeXtMidas send their messages to `processMessage` (this will be discussed in the section on Macro Graphics).