TransField object
Sets the part of the TransField. Using this method you can name a transaction field which is to contain:
Data from a field that already exists on the form definition (send the field name)
A system variable (send the name of an existing system variable)
Headers or other text (send your own name for the transaction field)
Your own numerical field (send your own name for the transaction field)
Components of transaction fields (FORMS Help topic)