QUESTION
 How do I create a global variable?

ANSWER
 The recommended way for declaring a global variable
 in VisualAge is:

 Since the name of global variables are nothing more than keys in
 the Smalltalk dictionary, adding a new global variable is done by
 adding a new key to this dictionary. For example, the following
 statement adds a new global variable called MyCustomers with a
 value of nil:

 Smalltalk at: #MyCustomers put: nil.

 (Note that the global variable should begin with a capital letter).
 If you subsequently want the variable, just execute:
 MyCustomers := <value>.

 Even with this method, you have to be very careful that 'MyCustomers'
 is not already an existing global (for example, a class) or you
 may break the system.

 One should avoid the use of global variables in applications, if at
 all possible.  The use of global variables violates the principle
 of data encapsulation.  Many times adding a new object or adding
 behavior to an existing object will provide the same function as
 a global variable.