Infotype 2 upload program

Hi Friends,

I have upload program to upload the infotype 2 Master Data to SAP, following FMs I am using,

I would like to modify the data if the record is already existing with Pernr, start date and end date.

If the Record is not available, I want to create new record.

BAPI_EMPLOYEE_ENQUEUE

CALL FUNCTION 'HR_INFOTYPE_OPERATION'

           EXPORTING

             infty             = '0002'

             number         = ls_infotype0002-pernr

             subtype        = ''

             record          = ls_infotype0002

             operation      = 'MOD'

             nocommit     = ''

             tclas            = 'A'

             dialog_mode = '0'

           IMPORTING

             return           = ls_return.

BAPI_EMPLOYEE_DEQUEUE

Above code is not working for updating the existing record.

Thanks,

Prasad.