Data are not saved to database – Auto creating new datafile in oracle

I have some problem with Oracle database. Before it works like that, if INDX[Counter].dbf file reach its maximum size (8GB) Oracle automatically created new datafile INDX[Counter+1].dbf. But on server wasn’t enough size to create new datafile. I increased space on server, I created new datafile manually:

ALTER TABLESPACE INDX2
ADD DATAFILE 'D:oracleproduct10.2.0oradataprofiINDX18.DBF' 
SIZE 4M
AUTOEXTEND ON NEXT 4M
MAXSIZE 8G;

Right now after INDX18.dbf reach 8GB Oracle wasn’t create new datafile automatically and data are no longer stored. I had to add new datafile manually. How to set Oracle database to auto create new data file after reach maximum size of single datafile?

Best regards