DIM A!            ' global 
 DIM B!            ' global 
 DIM C!            ' global 
 
 C! = 100.123     '<<< This value should not change! 
 B! = 123         '<<< This value should not change! 
 A! = Fun!(B!, C!) '<<< C allows type translation automatically! 
 
 PRINT "The value of A! = ", A!
 PRINT "The value of B! should still be <123> ...", B!
 
 FUNCTION Fun! (Y, Z)
   DIM A$
   DIM B!
   A$ = "Hello from inside our function!"    ' a local string variable 
   PRINT A$
   'The B! variable below is the local 
   'The C! variable is the global variable 
   'The Z variable is the function parameter Variable 
   B! = 3 * Z + C! + Y
   FUNCTION = B!
 END FUNCTION

Result:

 Hello from inside our function!
 The value of A! =  523.123
 The value of B! should still be <123> ... 123