Import statemnt is not getting one of the field in internal table

Hi

I am running two programs YP1 AND YP2 , in yp1 I am exporting the data to yp2, in YP1 all of the field is present including wtjhr which is field of bpja stucutre, but when I import the data in yp2 , all of the is field is displaying correctly but wtjhr is showing zero  ,I checked the corresponding structure bpja in which wtjhr is updated correctly, but when I imported data this value showing null value,

Here is my import/export statement in both reports

in yp1:

export tab4 from tab4 to database indx(st)  from wa_indx id indxkey.
free memory id  sy-uname.

And in Yp2

import
              tab4 = tab4 from database  ypindx(st)  id indxkey
              to wa_indx.

Please help me in this regard as I am new to abap I have goggled this  problem but could not find any help ,

Thanks in Advance.