modifycricprop() error

[ouborg@xxxxxxxx]

I'm trying to use the modifycricprop function, however, everytime I 
get the error:

error: attempt to call global'modifycricprop'(a nil value)

The lua code I use is below:

---------------------------------
-- TEST
---------------------------------
save_femm_file("block_1.fem")

new_current = 800
modifycricprop("Current Out",1,new_current)	


save_femm_file("block_1.fem")


block_1.fem has "Current Out" defined. I looked at the 3phasecable 
example, was was actually able to run the code on my machine; 
the .lua script for 3phase uses modifycricprop(). Any ideas on what 
the problem might be?

Thanks for any help,

Willem