BARCODE in CR11

SOLVED

I am trying to add a Barcode to our Pick Tickets,  we are on MAS v 4.5.

we have a Formula Field that is called BarcodePrice

the formula is:

formula = BarcodeC128B(ToText({SO_PickingSheetWrk.UnitPrice}))

but when i add the field to my report i get a popup that says Unable to view Picking Sheet Printing.  A number, currency amount, boolean, date-time or string is expected here.

where does it get the function BarcodeC128B from, i dont see that in my list of functions.  

Peter