BDC DUMP IN Function Module

Hi

I have created bdc program in FM .

After the below statement it is going to dump.

subrc = 0.

PERFORM bdc_field USING 'RP50G-PERNR'

<fs>-pernr.

FORM BDC_FIELD USING FNAM FVAL.

IF fval <> NODATA_CHARACTER. " After This Line coming Dump

CLEAR BDCDATA.

BDCDATA-FNAM = FNAM.

BDCDATA-FVAL = FVAL.

APPEND BDCDATA.

ENDIF.

ENDFORM.

Error

Unable to interpret "/" as a number.

and also am using standard include program BDCRECXY in my FM

How i can resolved .

Thanks

Sandy