Subsystem Journal Entries

Currently our business enters journal entries manually into PeopleSoft for our Cash Management function.  We are in the process of converting that into journal entries that we automatically create for them using sub-system journal entry.  When the business enters the journals, they have an Business unit on the header of say '10001'.  With the lines, they have business units of '10001' and '10002'.  We are attempting to replicate that using FS_JGEN (sub-system journal Entries), but are unable to get the one journal entry.  Instead we are getting two separate journal entries, one for '10001' and one for '10002'.  Bottom Line