File Operations in REXX

[leo6]

Hi ,

The piece of code that I am executing is :

parse upper arg inpf
i=1
say i
say "dsname passed from jcl is:"
say inpf
"Alloc Fi(IO) Da('"inpf"') Shr Reu"
"Execio * DiskRU IO (Stem IO.)"
Do i = 1 to IO.0
IO.i = overlay(' ', IO.i, 1)
End
"Execio * DiskW IO (Stem IO. Finis)"
"Free Fi(IO)"
say IO.0 "lines were replaced with spaces"
exit

/****.....end.........*****/

The error for the above code execution is :

READY
CHREXX4 TP.ECRM.GDGDATE1
1
dsname passed from jcl is:
TP.ECRM.GDGDATE1
Record cannot be updated. No record from file IO has been read for update.
EXECIO error while trying to GET or PUT a record.
FILE IO NOT FREED, DATA SET IS OPEN
5 lines were replaced with spaces
READY
END

......

could you help me in this , please??