Message No. RSBK257 and Message No. RSBK229 Data package error in DTP

Hi Guys,

Error occurred while running DTP, I have loaded data from flat file which contains key fig and char but some of key fig contains char value like n/a that I dont want in target for that I have written code in start routine

LOOP AT SOURCE_PACKAGE ASSIGNING <SOURCE_FIELDS>.

DELETE SOURCE_PACKAGE WHERE PANE1FILTER3LEVE  = 'n/a' AND PANE1FILTER6LEVE = 'n/a'.

ENDLOOP.

kindly suggest what I have to do for the same.

Thanks,

Pankaj