[FX.php List] edit related fields

[Test]

I'm working on a project using fx.php w/ Filemaker 7.02 server advanced on Xserve running 10.3.8. Everything works fine when all the fields on the layout are from the table the layout based on. I can also use fx.php to retrive value from the layout with related fields. However, when I tried to modify the value of any related field, I'll get error code 101, which according to FMP doc means record is missing, even though I can retrive the data for that record in fx.php (yes, all related fields are within a portal).

I tried to send command like

http://127.0.0.1/fmi/xml/FMPXMLRESULT.xml?-db=CTD&-lay=step1&ID=101&table::field1.1=Dr&-edit

 in the browser to FMP7 directly, but still getting the same error in xml result. So I thought maybe the problem is in Filemaker. However, I just found out if I send this command in browser to filemaker

http://127.0.0.1/fmi/xml/FMPXMLRESULT.xml?-db=CTD&-lay=step1&ID=101&table::field1.23=Dr&-edit

the related record will be updated without any problem. It seems that I have to specify the filemaker interal RecordID for the related field in the related table in order to edit the field. However, because FX is using FMPXMLRESULT.xml instead of fmresultset.xml, there's no easy way for me to find out the internal RecordID for the related field by just making 1 FMFind() call on the parent record. Any suggestion on what I should do in order to edit the related fields w/ fx?

chuck