Have you added the field to the form? Basically, UDF are not placed on system forms unless you add them using code.
If you added the field, please use the its uniqueId as you've defined while adding.
If not - either add it or get the value using a different way:
Dim oComent2 = oForm.DataSources.DbSataSources.Item("ORDR").GetValues("field",0)
Beni.
