Problem FM GUI_UPLOAD

Hi,all.

there,a problem in my pg.

I want to upload a txt file from local,and i used the GUI_UPLOAD FM to deal with it.But a mistake appears.

<b>'Cannot interpret data in file'</b>.

parts of the code as follows:

CALL FUNCTION 'GUI_UPLOAD'

EXPORTING

FILENAME = gv_file

• FILETYPE = 'ASC'

• HAS_FIELD_SEPARATOR = ' '

• HEADER_LENGTH = 0

• READ_BY_LINE = 'X'

• DAT_MODE = ' '

• CODEPAGE = ' '

• IGNORE_CERR = ABAP_TRUE

• REPLACEMENT = '#'

• CHECK_BOM = ' '

• VIRUS_SCAN_PROFILE =

• NO_AUTH_CHECK = ' '

• IMPORTING

• FILELENGTH =

• HEADER =

TABLES

DATA_TAB = in_tab

• EXCEPTIONS

• FILE_OPEN_ERROR = 1

• FILE_READ_ERROR = 2

• NO_BATCH = 3

• GUI_REFUSE_FILETRANSFER = 4

• INVALID_TYPE = 5

• NO_AUTHORITY = 6

• UNKNOWN_ERROR = 7

• BAD_DATA_FORMAT = 8

• HEADER_NOT_ALLOWED = 9

• SEPARATOR_NOT_ALLOWED = 10

• HEADER_TOO_LONG = 11

• UNKNOWN_DP_ERROR = 12

• ACCESS_DENIED = 13

• DP_OUT_OF_MEMORY = 14

• DISK_FULL = 15

• DP_TIMEOUT = 16

• OTHERS = 17

and the data in the file are came from table SPFLI,separated by SAPCE.

THANKS.