selection table multiple entries

I am trying to submit SD70AV3A to print billing document.

I am taking Doc no as select-options. Program should take in doc no, get all output type & transmission med for the doc no. Submitting works well if doc no is a parameter, if it is a range, it is only doig it for th elow field. I have a seltab like rsparams.

data: begin of seltab occurs 0.

include structure rsparams.

data: end of seltab.

start-of-selection.

select kschl nacha anzal dimme delet from nast into corresponding

fields

of itab where

objky in s_vbeln and KAPPL = 'V3'.

append itab.

endselect.

sort itab by kschl.

read table itab index 1.

i_kschl = itab-kschl.

describe table itab lines n.

read table itab index n.

l_kschl = itab-kschl.

seltab-selname = 'rg_vbeln'.

seltab-kind = 'S'.

seltab-sign = 'I'.

seltab-option = 'BT'.

seltab-low = s_vbeln-low.

seltab-high = s_vbeln-high.

append seltab.

seltab-selname = 'rg_kschl'.

seltab-kind = 'S'.

seltab-sign = 'I'.

seltab-option = 'BT'.

seltab-low = i_kschl.

seltab-high = l_kschl.

append seltab.

seltab-selname = 'rg_nacha'.

seltab-kind = 'S'.

seltab-sign = 'I'.

seltab-option = 'BT'.

seltab-low = '1'.

seltab-high = '8'.

append seltab.

IF reissue = 'X'.

SUBMIT SD70AV3A via selection-screen

with selection-table seltab.

.

..

Any suggestion is appreciated.