OPENDATA SET creating file error

Hi experts,

i am working on creating a text file in Application server using OPNDATASET. i have codes as below:

path = /user/sap/data/txt

OPEN DATASET path FOR OUTPUT IN text MODE .

loop at t_cmex.

transfer t_cmex to path.

endloop.

close dataset path.

but when the open data statment executes its gving sy-subrc = 8 and not creating the file.

plz help me with the same.

mahesh