BDC for deleting delivery

hi All,

I am writing a BDC for removal of outbound delivery from manifest as

**--Record the BDC for deleting deliveries from Manifest

REFRESH bdcdata.

CLEAR bdcdata.

REFRESH messtab.

PERFORM bdc_dynpro USING 'SAPMV56A' '1011'.

PERFORM bdc_field USING 'BDC_CURSOR'

'VTTK-TKNUM'.

PERFORM bdc_field USING 'BDC_OKCODE'

'=MM_TKAL'.

PERFORM bdc_field USING 'VTTK-TKNUM'

w_manifest.

PERFORM bdc_dynpro USING 'SAPMV56A' '1020'.

PERFORM bdc_field USING 'BDC_OKCODE'

'=MM_UETP'.

PERFORM bdc_field USING 'BDC_CURSOR'

'VTTK-TDLNR'.

CALL TRANSACTION 'VT02N' USING bdcdata

MODE ws_mode

UPDATE ws_update

MESSAGES INTO messtab.

but if i run this the delivery is not getting deleted.

Please help.....

Thanks ,

Ruchi Tiwari