FTP incoming access problem

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Hi,Everybody!
  I'm working on RH 6.0. And I have configure Ftp service by system internal.
Other people that work at the local network can see the incoming folder and others.
I have chmod the /home/ftp/incoming to -rwxrwxrwx. But none can upload file to the
folder. 
  Can you tell How to start ftp service and /incoming folder can be upload file(s).
  Thanks.