Stop Sales Order Processing

[in2solutions]

Software: Jiwa 6.513
I would like to insert some breakout code when the operator clicks Record \ Process on a sales order.

Effectively I am wanting to stop the sales order processing when their sales division is set to “USD”
I have the following code:
If SalesOrderObject.BranchID = “023524BC1C1D4E8086E2” then
MsgBox “USD Branch. Order Cannot Be Processed”
rtnCancel = True
End If

This does not seem to work. Can you let me know which breakout this should go against and if this code is correct.
Regards,
George