HI Archana,
Sample code
*---Report with selection screen and to display the list of
* possible entries for field 'B' as per the value in field 'A'.
parameters: p_vbeln type vbak-vbeln,
p_posnr type vbap-posnr.
at selection-screen on value-request for p_posnr.
data: begin of help_item occurs 0,
posnr type vbap-posnr,
matnr type vbap-matnr,
arktx type vbap-arktx,
end of help_item.
data: dynfields type table of dynpread with header line.
dynfields-fieldname = 'P_VBELN'.
append dynfields.
call function 'DYNP_VALUES_READ'
exporting
dyname = sy-cprog
dynumb = sy-dynnr
translate_to_upper = 'X'
tables
dynpfields = dynfields
exceptions
invalid_abapworkarea = 1
invalid_dynprofield = 2
invalid_dynproname = 3
invalid_dynpronummer = 4
invalid_request = 5
no_fielddescription = 6
invalid_parameter = 7
undefind_error = 8
double_conversion = 9
stepl_not_found = 10
others = 11.
read table dynfields with key fieldname = 'P_VBELN'.
p_vbeln = dynfields-fieldvalue.
call function 'CONVERSION_EXIT_ALPHA_INPUT'
exporting
input = p_vbeln
importing
output = p_vbeln.
select posnr matnr arktx into table help_item
from vbap
where vbeln = p_vbeln.
call function 'F4IF_INT_TABLE_VALUE_REQUEST'
exporting
retfield = 'POSNR'
dynprofield = 'P_POSNR'
dynpprog = sy-cprog
dynpnr = sy-dynnr
value_org = 'S'
tables
value_tab = help_item.