Passing variables between functions

Gidday,

Basically what I am looking to do is run one Autolisp function that will define a global variable and then have another function use that variable. Both functions need to be able to be run from the command line or from a button on the ribbon at any time (the second will be error trapped so, if the first hasn't been run and the variable hasn't been defined, it will return a sensible error).

What I am trying is something like this:

(defun c:CreateVariable ( / localVariable1 localVariable2)
 (setq localVariable1 50.0)
 (setq localVariable2 3.0)
 (setq globalVariable (* localvariable1 localVariable2)
) ; end defun

(defun c:UseVariable ()
 (setq newVariable (/ 1234.0 globalVariable))
 (princ (rtos newVariable))
) ; end defun

I know that if you define a function using c: xxxx it wont let you use arguments but I don't know how to get that global variable into the function...

I'm sure it's simple, but at the moment it's very frustrating.

Any help would be appreciated.

Introduce a test that will run the CreateVariable if the globalVariable has not been defined

 (if
 (not globalVariable) ;test expression
 (c:CreateVariable) ;preform the function
 )

See the test expressions COND, IF, AND OR in the AutoLISP help file for more info

(defun c:CreateVariable ( / localVariable1 localVariable2)
 (setq localVariable1 50.0)
 (setq localVariable2 3.0)
 (setq globalVariable (* localvariable1 localVariable2))
) ; end defun

(defun c:UseVariable ()
  
 ;Either the variable has a value or assign one
 (or globalVariable (c:CreateVariable))

 (setq newVariable (/ 1234.0 globalVariable))
 (princ (rtos newVariable))
) ; end defun