Hi,
Write your code at PAI (Process After Input ).
if design the screen field with same name as table fields.
Use.
Data wa type ztable.
MOVE-CORRESPONDING ztable (module pool) to wa.
OR
wa-field1 = ztable-field1(modulepool).
OR
use Import and Export to fetch the values.
Hope it helpful.
Regards,
Ramesh.V